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Difference between revisions of "Sonic the Hedgehog 2 (16-bit)/Hidden content"

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==Lost Sprites==
+
{{back}}
{|class="prettytable"
+
 
!Artwork||Name||Description
+
==Level select==
 +
{{HiddenContent
 +
| image1=S2 level select.png
 +
| desc=Play songs 19, 65, 09, 17 on the options screen, then hold {{A}}+{{start}} on title screen.
 +
}}
 +
==[[Edit mode]]==
 +
{{HiddenContent
 +
| image1=Sonic2 MD DebugMode.png
 +
| desc=From the level select menu, play songs 01, 09, 09, 02, 01, 01, 02, 04 (1992-11-24 - the worldwide launch date of ''Sonic 2''). A [[Ring]] sound should trigger. Select a Zone and hold {{A}} until the title card disappears.
 +
 
 +
Edit mode does not work when playing as [[Miles "Tails" Prower|Tails]] in this game, even though the counters for debug mode are still intact here.
 +
}}
 +
 
 +
==[[Night mode]]==
 +
{{HiddenContent
 +
| image1=Sonic2 MD NightMode.png
 +
| desc=After enabling edit mode, select a level on the level select screen and hold {{C}}+{{Start}} until the title card disappears.
 +
}}
 +
==Get all Chaos Emeralds==
 +
{{HiddenContent
 +
| noimage=yes
 +
| desc=From the level select menu, play songs 04, 01, 02, 06 on the sound test and a [[Chaos Emerald]] sound effect will trigger. This immediately gives the player all seven Chaos Emeralds, enabling [[Super Sonic]].
 +
}}
 +
==Swap Tails for Miles==
 +
{{HiddenContent
 +
| image1=Sonic2 MD Comparison OptionsJP.png
 +
| desc=Press {{up}} {{down}} {{down}} {{down}} {{up}} at the title screen. This will cause all instances of "Tails" to change to "Miles", except in the Japanese version where the reverse will happen. This also toggles the trademark symbols on the Sega logo and the title screen.
 +
}}
 +
==[[Continue|14 continues]]==
 +
{{HiddenContent
 +
| image1=Sonic2 MD 14Continues.png
 +
| desc=Play songs 01, 01, 02, 04 on the options screen. An incorrect sound command is issued, causing [[Oil Ocean Zone]] music to continue playing until a reset.
 +
}}
 +
 
 +
==Unused content==
 +
===Art===
 +
{{UnusedTable|type=Art|
 +
{{UnusedRow
 +
| sprite=
 +
| desc=An animation very similar to one used in [[Wing Fortress Zone]] when [[Sonic the Hedgehog|Sonic]] grabs the panels on the side of the ship. However, this is vertical. Its frame IDs are '''52''' and '''53'''.
 +
}}
 +
{{UnusedRow
 +
| sprite=
 +
| desc=An alternate death frame for Sonic, defined in animation '''16''' with a frame ID of '''5E'''. This returns from (and is also unused in) ''[[Sonic the Hedgehog (16-bit)|Sonic the Hedgehog]]''.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Sonic2 MD Sprite CPZSirenLights.gif|2}}
 +
| desc=Unused decorative objects for [[Chemical Plant Zone]], stored at '''0x0383-0x0393''' in VRAM. These can be placed in the [[Sonic the Hedgehog 2 (2013)|iOS/Android 2013 version]]'s debug mode.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Spr_cpzboss.gif}}
 +
| desc=An animation for [[Water Eggman]] which shows [[Dr. Eggman]] dropping chemicals on himself. This animation has been around since the [[Sonic the Hedgehog 2 (Nick Arcade prototype)|Nick Arcade prototype]], but it was never implemented. A fix to implement the lost animation can be found [[SCHG How-to:Restore lost CPZ boss feature|here]].
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Sonic2 MD Sprite OOZSpringHolder.png}}
 +
| desc=A holder for [[Oil Ocean Zone]]'s ball and spring object (see below). This appeared in the Simon Wai prototype, and is still loaded into VRAM in the final game.
 +
}}
 +
{{UnusedRow
 +
| sprite=
 +
| desc=An unused animation for [[Aquis]] spitting up oil, along with an oil spray.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Balkiry2.png}}
 +
| desc=Unused frame of the [[Balkiry]] badnik with landing gear. It's possible that they were originally intended to take off from the [[Wing Fortress Zone]] as it passed by. If a Balkiry is selected in debug mode, this sprite will be seen instead of its flying one.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|S2-Turtle.gif|2}}
 +
| desc=Walking sprites of [[Tocky]], who pops out of the [[Badnik]]s in [[Sky Chase Zone]]. Normally the player will never see this, since the animal never has the opportunity to hit the ground. In order to see it, the player must use debug mode to create and destroy a Badnik while the Wing Fortress passes by. This animation would later make an appearance in ''[[Sonic Mania]]'', as Tocky can be found in [[Titanic Monarch Zone]].
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|S2-Picky.gif|2}}
 +
| desc=[[Picky]], a returning animal from the original ''Sonic the Hedgehog'', is present in [[Death Egg Zone]]. However, there are no Badniks or animal capsules, so he's never seen.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Sonic2-RobotnikLaugh.gif|2}}
 +
| desc=In [[Death Egg Zone]], getting hit with one or more [[Ring]]s during the [[Mecha Sonic (Death Egg Zone boss)|Mecha Sonic]] battle causes Eggman to laugh. However, this is never actually seen outside of debug mode because the Zone has no Rings. In the 2013 mobile remake, this animation can be seen normally if the player dies during the fight.  In ''[[3D Sonic the Hedgehog 2]]'' it can also be seen if the player is hurt by Mecha Sonic if the Ring Keeper mode is on.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|HPZiconS2.png|2}}
 +
| desc=Level Select icon for [[Hidden Palace Zone]], which never made it into the final game.  The art however, is present in [[Sonic the Hedgehog 3|''Sonic 3''<nowiki>'</nowiki>s]] level select. Pro Action Replay code '''0096D8:0303''' will cause it to replace the [[Emerald Hill Zone]] icon in the Stage Select.
 +
}}
 +
}}
 +
 
 +
===Objects===
 +
{{UnusedTable|type=Art|
 +
{{UnusedRow
 +
| sprite={{spriteImage|S2 static monitor.png|2}}
 +
| desc=A static or blank [[monitor]] which harms the player when broken. Never seen in-game. To see it, a monitor's subtype should be set to '''00'''.
 +
}}
 +
{{UnusedRow
 +
| sprite=
 +
| desc=A hovering platform for [[Chemical Plant Zone]] that has been around since the Nick Arcade prototype. Every 1024 frames, it will slowly rise up for 128 frames, float in the air, then come back down 128 frames later. The amount of time it floats in the air is 128*(lower four bits of subtype) frames. The upper four bits can be used to offset when it starts to rise in the air. Its object ID is '''$0C'''.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Aquatic ruin door.png}}
 +
| desc=Unused door barriers from [[Aquatic Ruin Zone]], which function like the door barriers found in other Zones. This can be placed with debug mode.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Sonic2-mrzobject.png}}
 +
| desc=A strange platform made of [[Ring]]s, placeable using debug mode in [[Mystic Cave Zone]]. When placed, this object will slowly swing in an anti-clockwise direction and can be stood on. This object has existed since the [[Sonic the Hedgehog 2 (Simon Wai prototype)|Simon Wai prototype]], and its object ID is '''$73'''.
 +
}}
 +
{{UnusedRow
 +
| sprite=
 +
| desc=A ball and spring object, which can be placed in [[Oil Ocean Zone]] via debug mode. If a [[button]] is placed near it and pressed, the ball will pop out and start rolling in whichever direction Sonic was facing when the object was placed. It seems this object would have been used to cross something, as it can be stood upon, much like the ball object that appeared in early versions of ''[[Sonic the Hedgehog (16-bit)|Sonic the Hedgehog]]''. It does not collide with breakable floors or elevators, and it will go up slopes and even vertical walls without slowing or stopping. It is used in the Simon Wai and [[Sonic the Hedgehog 2 (alpha)|Aug 21st Alpha]] prototypes. Its object ID is '''$46'''.
 +
}}
 +
{{UnusedRow
 +
| sprite={{SpriteImage|Sonic2Alpha MD Sprite OOZTube.png}}
 +
| desc=Horizontal versions of the breakable pressure stopper in Oil Ocean Zone exist. These can be jumped on, but they will send Sonic and Tails left or right rather than up. Once Sonic is travelling, the player can't make him stop unless he collides with an object - even in edit mode the player will continue to travel. This would have been used in the Simon Wai layout of the Zone, but has no purpose in the final layout.
 +
}}
 +
{{UnusedRow
 +
| sprite=
 +
| desc=Although very similar to the small platforms used in [[Metropolis Zone]], this platform behaves strangely, usually rising at an angle. Its object ID is '''$6C'''.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Sonic2-giantlaser.gif}}
 +
| desc=Large laser shooting through a spinning platform in [[Wing Fortress Zone]]. If the sub-ID of the spinning platforms has bit '''02''' of their subtype set but not '''04''', they will become this object. This object can be placed with debug mode, where it oddly appears before the used platform in the object list. Its object ID is '''$B7'''.
 +
}}
 +
{{UnusedRow
 +
| sprite={{spriteImage|Sonic2-wfz-spinnything2.gif|2}}
 +
| desc=Weird spinning pole in [[Wing Fortress Zone]] that acts like a [[Badnik]] - the player can destroy it, and it can hurt them, but it doesn't actually move. Its object ID is '''$BF''', and it is placeable with debug mode.
 +
}}
 +
{{UnusedRow
 +
| sprite=
 +
| desc=The emerald-shaped object that was used in Hidden Palace Zone to block off a tube. The graphics are long gone, but the code is still there. It's a simple solid indestructible object and its coding hasn't changed since the Nick Arcade prototype. Its object ID is '''$12'''.
 +
}}
 +
{{UnusedRow
 +
| sprite=
 +
| desc=The waterfall object from Hidden Palace Zone, which is also left over. Again, the graphics no longer exist in the ROM. Its height is equal to 16*(lower five bits of subtype)+16 pixels. Placing one with a subtype greater than '''17''' will spawn garbage objects on the right. Its object ID is '''$13'''.
 +
}}
 +
{{UnusedRow
 +
| sprite=
 +
| desc=The spinning log spikes from ''[[Sonic the Hedgehog (16-bit)|Sonic the Hedgehog]]''<nowiki>'</nowiki>s [[Green Hill Zone]]. Unfortunately, the graphics have been deleted, but the coding is intact. Its object ID is '''$17'''.
 +
}}
 +
}}
 +
 
 +
===Score tally===
 +
{{HiddenContent
 +
| image1=Sonic2UnusedScoreTally.png
 +
| desc=This configuration of the score tally is unused but was meant for levels with a single Act ([[Sky Chase Zone]], etc). It can be made to appear by using debug mode and placing, then breaking a capsule.
 +
}}
 +
 
 +
===Audio===
 +
 
 +
====Music====
 +
In the sound test, song $10 is a unused song. This has been established to be the music meant for [[Hidden Palace Zone]].
 +
 
 +
====Sound effects====
 +
Sounds not used anywhere in the game can be heard in the sound test, some of which are leftovers from the original ''[[Sonic the Hedgehog (16-bit)|Sonic the Hedgehog]]''.
 +
{| class="prettytable" style="width:auto;"
 +
!Audio !!ID !!Description
 
|-
 
|-
|[[Image:Aquatic ruin door.png|center]]||ARZ Barrier||Unused door barriers from [[Aquatic Ruin Zone]].
+
!colspan=3|''Sonic the Hedgehog'' leftovers
 
|-
 
|-
|[[Image:Balkiry2.png|center]]||Unused Balkiry Frame||Unused frame of the [[Balkiry]] badnik with landing gear.
+
|[[File:Sonic2 MD Sound29.ogg]]
 +
|'''29'''
 +
|The sound for touching the R, Up, and Down [[Special Stage (Sonic the Hedgehog 16-bit)|Special Stage]] blocks.
 
|-
 
|-
|[[Image:S2-Turtle.gif|center]]||Walking Turtle||Walking sprites of the turtles that pop out of the badniks in [[Sky Chase Zone]]. Normally you'll never see this, since the animal never has the opportunity to hit the ground.
+
|[[File:Sonic2 MD Sound31.ogg]]
 +
|'''31'''
 +
|[[Scrap Brain Zone]] electricity.
 
|-
 
|-
|[[Image:HPZiconS2.png|center]]||HPZ Icon||Level Select icon for [[Hidden Palace Zone]], which never made it into the final game.  The art however, is present in [[Sonic the Hedgehog 3|Sonic 3's]] level select.
+
|[[File:Sonic2 MD Sound3A.ogg]]
 +
|'''3A'''
 +
|The sound for touching the colour-changing diamonds in the Special Stage.
 
|-
 
|-
|[[Image:Sonic2-giantlaser.gif|center]]||WFZ Laser||Large laser shooting through a spinning platform in [[Wing Fortress Zone]]. Never seen in-game.
+
|[[File:Sonic2 MD Sound43.ogg]]
 +
|'''43'''
 +
|The sound for entering [[Giant Ring]]s at the end of an Act.
 
|-
 
|-
|[[Image:Sonic2-mrzobject.png|center]]||MCZ Ring Platform||Weird platform made of rings, placeable using debug mode. It moves back and forth depending on which side you stand on.
+
|[[File:Sonic2 MD Sound47.ogg]]
 +
|'''47'''
 +
|The chain pulling sound from [[Marble Zone]].
 
|-
 
|-
|[[Image:Sonic2-wfz-spinnything2.gif|center]]||WFZ Spinning Pole||Weird spinning pole that acts like a badnik - you can destroy it, and it can hurt you, but it doesn't actually move.
+
|[[File:Sonic2 MD Sound49.ogg]]
 +
|'''49'''
 +
|The bonus point tags found at the end of an Act.
 
|-
 
|-
|[[Image:S2 static monitor.png|center]]||Static or blank TV Monitor||Powerup monitor which harms you when broken. Never seen in-game.
+
!colspan=3|Other sounds
 
|-
 
|-
 +
|[[File:Sonic2 MD Sound38.ogg]]
 +
|'''38'''
 +
|Sounds similar to the sound of spikes popping up. Also unused in ''Sonic 1''.
 +
|-
 +
|[[File:Sonic2 MD Sound51.ogg]]
 +
|'''51'''
 +
|Unknown. Sounds like something popping or skidding on the ground.
 +
|-
 +
|[[File:Sonic2 MD Sound52.ogg]]
 +
|'''52'''
 +
|A low siren, similar to '''$53''' which is used in the 2-Player mode.
 +
|-
 +
|[[File:Sonic2 MD Sound68.ogg]]
 +
|'''68'''
 +
|Sounds like a slightly shorter version of Mystic Cave Zone's bridges stopping in place ('''$69''').
 
|}
 
|}
  
==Unused Music Track==
+
==Level slots==
In the sound test, song $10 is actually a unused song. This has been established to be the music meant for [[Hidden Palace Zone]].
+
Like its predecessor, ''Sonic 2'' on the Mega Drive lays out its levels in a different order internally to how the player sees them when playing through the game. It gives some clues as to what the original progression looked like, and the differences are quite significant.
  
==True Level Order==
+
The internal level order can be seen by using [[Pro Action Replay]] code (FFFE10:??00), substituting the question marks with the hexadecimal values for the level slots described in the table below and then attempting to enter any level (any number past 10 crashes the game). [[Metropolis Zone]] covers two level slots as it has three Acts.
The level order that is used during gameplay is actually quite different from the intended order according to the level slots. A simple level select [[Pro Action Replay]] code (FFFE10:??00) can be used to verify this:
+
 
{|class="prettytable"
+
{|class="prettytable sortable" style="width:auto;"
! Order in gameplay||Actual
+
! Level slot
 +
! Level name
 +
! In-game order
 +
! Comments
 +
|-
 +
| 00
 +
| [[Emerald Hill Zone]]
 +
| 01
 +
|
 +
|-
 +
| 01
 +
| Unknown
 +
|
 +
| Plays Emerald Hill Zone's music.
 +
|-
 +
| 02
 +
| [[Wood Zone]]
 +
| Scrapped
 +
| Palette is all that remains. Plays Metropolis Zone's music.
 +
|-
 +
| 03
 +
| Unknown
 +
|
 +
| Plays Oil Ocean Zone's music.
 +
|-
 +
| 04
 +
| [[Metropolis Zone]]
 +
| 08
 +
|
 +
|-
 +
| 05
 +
| [[Metropolis Zone]] (Act 3)
 +
| 09
 +
|
 
|-
 
|-
|Emerald Hill Zone
+
| 06
|Emerald Hill Zone (00)
+
| [[Wing Fortress Zone]]
 +
| 11
 +
|
 
|-
 
|-
|Chemical Plant Zone
+
| 07
|Metropolis Zone (04/05)
+
| [[Hill Top Zone]]
 +
| 05
 +
|
 
|-
 
|-
|Aquatic Ruin Zone
+
| 08
|Wing Fortress Zone (06)
+
| [[Hidden Palace Zone]]
 +
| Scrapped
 +
| Palette and object/ring locations remain. Plays unused track #10.
 
|-
 
|-
|Casino Night Zone
+
| 09
|Hill Top Zone (07)
+
| Unknown
 +
|
 +
| Plays Sky Chase Zone's music.
 
|-
 
|-
|Hill Top Zone
+
| <span style="display:none;">10</span>0A
|Oil Ocean Zone (0A)
+
| [[Oil Ocean Zone]]
 +
| 07
 +
|
 
|-
 
|-
|Mystic Cave Zone
+
| <span style="display:none;">11</span>0B
|Mystic Cave Zone (0B)
+
| [[Mystic Cave Zone]]
 +
| 06
 +
|
 
|-
 
|-
|Oil Ocean Zone
+
| <span style="display:none;">12</span>0C
|Casino Night Zone (0C)
+
| [[Casino Night Zone]]
 +
| 04
 +
|
 
|-
 
|-
|Metropolis Zone
+
| <span style="display:none;">13</span>0D
|Chemical Plant Zone (0D)
+
| [[Chemical Plant Zone]]
 +
| 02
 +
|
 
|-
 
|-
|Sky Chase Zone
+
| <span style="display:none;">14</span>0E
|Death Egg Zone (0E)
+
| [[Death Egg Zone]]
 +
| 12
 +
| Occupied by [[Genocide City Zone]] in prototypes.
 
|-
 
|-
|Wing Fortress Zone
+
| <span style="display:none;">15</span>0F
|Aquatic Ruin Zone (0F)
+
| [[Aquatic Ruin Zone]]
 +
| 03
 +
|
 
|-
 
|-
|Death Egg Zone
+
| <span style="display:none;">16</span>10
|Sky Chase Zone (10)
+
| [[Sky Chase Zone]]
 +
| 10
 +
|
 
|}
 
|}
  
Level slots 01,02,03,05,09 all lead to Emerald Hill Zone and 08 is actually Hidden Palace. In the [[Sonic the Hedgehog 2 (Simon Wai prototype)| Simon Wai prototype]] some of these were used for scrapped levels. 02 was used for [[Wood Zone]] and 0E was used for [[Genocide City Zone]].
+
This order is mirrored (with empty slots cut out) by some prototype level select screens. All empty slots are fundamentally broken, loading varying amounts of graphics data from Emerald Hill Zone (depending on the build).
 +
 
 +
Three slots in the game remain empty in all versions of ''Sonic 2'' (save for the very early [[Sonic the Hedgehog 2 (Nick Arcade prototype)|Nick Arcade prototype]] which is using the ''Sonic 1'' level order). There has been much speculation over the years about what these slots were reserved for (if anything) - possible candidates include [[Brenda Ross]]'s "desert" and "winter" zones which were thought to be at least partially complete, or possibly Genocide City Zone before it was transformed into Metropolis Zone Act 3. The team are known to have explored many level ideas during development, most of which did not make it past the design stage.
 +
 
 +
Commentary found in the ''[[Sonic Jam]]'' strategy guide reveals that the level order could have been even more different. It states that [[Chemical Plant Zone]] was meant to be the 10th Zone back when the game was planned as an 18-Zone game.
 +
 
 +
<gallery>
 +
DHZBetaLeftovers.PNG|Slot 03 in the [[Sonic the Hedgehog 2 (Simon Wai prototype)|Simon Wai prototype]].
 +
DHZFinalLeftovers.PNG|Slot 03 in the final game.
 +
</gallery>
 +
 
 +
==Inaccessible Rings==
 +
There are some levels that have Rings in places that can't be reached normally. This makes getting a [[Perfect Bonus]] in these stages impossible.{{ref|1=http://tcrf.net/Sonic_the_Hedgehog_2_(Genesis)#Inaccessible_Rings}}
 +
 
 +
{| class="prettytable"
 +
!style="width:320px"|Screenshot
 +
! Level
 +
! Approximate coordinates
 +
! Description
 +
|-
 +
|{{Bobscreen|Sonic2AquaticRuinZone-Rings.png}}
 +
|Aquatic Ruin Zone Act 2
 +
|1FA90626
 +
|Two horizontally lined rings.
 +
|-
 +
|{{Bobscreen|Sonic2CasinoNightZone-Rings.png}}
 +
|Casino Night Zone Act 2
 +
|027F00F8
 +
|Two groups of seven rings. These are right at the start of the level but cannot be reached with a jump or using nearby objects.
 +
|-
 +
|{{Bobscreen|Sonic2MysticCaveZone-Rings1.png}}{{Bobscreen|Sonic2MysticCaveZone-Rings2.png}}
 +
|Mystic Cave Zone Act 2
 +
|16050156<br>1712016D
 +
|Three horizontally lined rings, and a nearby curve of rings, similar to ones found near swings. Both sets of rings are found in the ceiling.
 +
|-
 +
|{{Bobscreen|Sonic2OilOceanZone-Rings1.png}}{{Bobscreen|Sonic2OilOceanZone-Rings2.png}}{{Bobscreen|Sonic2OilOceanZone-Rings3.png}}
 +
|Oil Ocean Zone Act 2
 +
|1A0001F8<br>0B9F03B0<br>1245021C
 +
|Three horizontally lined rings, close to the launcher and invincibility monitor. Three vertically lined rings stuck in a block which prohibits access to them. Rings in a upside down v shape pattern. They are stuck inside the wall, thus unaccessable.
 +
|-
 +
|{{Bobscreen|Sonic2MetropolisZone-Rings.png}}
 +
|Metropolis Zone Act 2
 +
|02C0043F
 +
|Three slanted rings, in the floor that has a ten-ring monitor and a cog close-by.
 +
|}
 +
 
 +
==Scrapped Zone remnants==
 +
There are small remnants of [[Hidden Palace Zone]], [[Wood Zone]], [[Genocide City Zone]], and [[Dust Hill Zone]] in the final game. See the aforementioned level pages for more information.
 +
 
 +
==Cheat device codes==
 +
These are cheat codes that can only be used with game enhancer devices. Support for these codes is available in most emulators. There are two versions of this game. If one code doesn't work on your game, then try the other.
 +
 
 +
===[[Game Genie (Mega Drive)|Game Genie]]===
 +
==== Official codes (REV00)====
 +
{{CodeTable|official=yes|
 +
{{CodeRow|SATA-DJTJ|[[Rings]] worth 2 (player 1). }}
 +
{{CodeRow|SATA-DNTJ|Rings worth 3 (player 1).}}
 +
{{CodeRow|SATA-DTTJ|Rings worth 4 (player 1).}}
 +
{{CodeRow|SATA-DYTJ|Rings worth 5 (player 1).}}
 +
{{CodeRow|SATA-D2TJ|Rings worth 6 (player 1).}}
 +
{{CodeRow|SATA-D6TJ|Rings worth 7 (player 1).}}
 +
{{CodeRow|SATA-DATJ|Rings worth 8 (player 1).}}
 +
{{CodeRow|AE8A-AADN|Start with 1 life instead of 3 (player 1).}}
 +
{{CodeRow|AY8A-AADN|Start with 5 lives (player 1).}}
 +
{{CodeRow|A68A-AADN|Start with 7 lives (player 1).}}
 +
{{CodeRow|BE8A-AADN|Start with 9 lives (player 1).}}
 +
{{CodeRow|DE8A-AADN|Start with 25 lives (player 1).}}
 +
{{CodeRow|GJ8A-AADN|Start with 50 lives (player 1).}}
 +
{{CodeRow|KN8A-AADN|Start with 75 lives (player 1).}}
 +
{{CodeRow|NN8A-AADN|Start with 99 lives (player 1).}}
 +
{{CodeRow|JW3A-CA4Y|Infinite lives (player 1).}}
 +
{{CodeRow|SATA-DJW8|Rings worth 2 (player 2).}}
 +
{{CodeRow|SATA-DNW8|Rings worth 3 (player 2).}}
 +
{{CodeRow|SATA-DTW8|Rings worth 4 (player 2).}}
 +
{{CodeRow|SATA-DYW8|Rings worth 5 (player 2).}}
 +
{{CodeRow|SATA-D2W8|Rings worth 6 (player 2).}}
 +
{{CodeRow|SATA-D6W8|Rings worth 7 (player 2).}}
 +
{{CodeRow|SATA-DAW8|Rings worth 8 (player 2).}}
 +
{{CodeRow|AE8A-AADW|Start with 1 life instead of 3 (player 2).}}
 +
{{CodeRow|AY8A-AADW|Start with 5 lives (player 2).}}
 +
{{CodeRow|A68A-AADW|Start with 7 lives (player 2).}}
 +
{{CodeRow|BE8A-AADW|Start with 9 lives (player 2).}}
 +
{{CodeRow|DE8A-AADW|Start with 25 lives (player 2).}}
 +
{{CodeRow|GJ8A-AADW|Start with 50 lives (player 2).}}
 +
{{CodeRow|KN8A-AADW|Start with 75 lives (player 2).}}
 +
{{CodeRow|NN8A-AADW|Start with 99 lives (player 2).}}
 +
{{CodeRow|JXGA-CA7W|Infinite lives (player 2).}}
 +
{{CodeRow|KBVT-CAE2|Jump lower.}}
 +
{{CodeRow|FVVT-CAE2|Jump a little higher.}}
 +
{{CodeRow|EBVT-CAE2|Jump a lot higher (Switch off if you get stuck somewhere or want to go in the water).}}
 +
{{CodeRow|CBVT-CAE2|Jump really high (Switch off if you get stuck somewhere or want to go in the water).}}
 +
{{CodeRow|A02T-CAGL|[[Sonic]] stays invincible for a shorter time after getting hit.}}
 +
{{CodeRow|982T-CAGL|Sonic stays invincible for a longer time after getting hit.}}
 +
{{CodeRow|ALTA-CA82|Sonic becomes invisible and invincible for the rest of the level after getting hit.}}
 +
{{CodeRow|ALTA-CA9Y|Once invincible [stars], Sonic stays Invincible for the rest of the level.}}
 +
{{CodeRow|ATTT-CA58|Sonic doesn't lose rings when hit.}}
 +
{{CodeRow|ATTT-CA6W |Tails doesn't lose rings when hit.}}
 +
{{CodeRow|ATTT-CA6W|Only 1 ring needed instead of 50 to enter special stage.}}
 +
{{CodeRow|SBJA-HJV2|Rings worth 2 in special stages (Sonic only/Doesn't show on screen).}}
 +
{{CodeRow|SBJA-HNV2|Rings worth 3 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HTV2|Rings worth 4 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HYV2|Rings worth 5 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-H2V2|Rings worth 6 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-H6V2|Rings worth 7 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HAV2|Rings worth 8 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HJV8|Rings worth 2 in special stage (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HNV8|Rings worth 3 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HTV8|Rings worth 4 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HYV8|Rings worth 5 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-H2V8|Rings worth 6 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-H6V8|Rings worth 7 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HAV8|Rings worth 8 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|ACZT-CACN|Need 0 chaos emeralds to become [[Super Sonic]] (Don't grab more than needed).}}
 +
{{CodeRow|AGZT-CACN|Need 1 Chaos Emerald to become Super Sonic (Don't grab more than needed). }}
 +
{{CodeRow|ALZT-CACN|Need 2 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|ARZT-CACN|Need 3 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|AWZT-CACN|Need 4 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|A0ZT-CACN|Need 5 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|A4ZT-CACN|Need 6 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|AGZT-CACY + K4ZT-CA92|Need 1 ring to become Super Sonic, don't lose rings with time.}}
 +
{{CodeRow|A0ZT-CACY |Need 5 rings to become Super Sonic.}}
 +
{{CodeRow|BLZT-CACY |Need 10 rings to become Super Sonic.}}
 +
{{CodeRow|DGZT-CACY|Need 25 rings to become Super Sonic.}}
 +
{{CodeRow|FCZT-CACY|Need 40 rings to become Super Sonic.}}
 +
{{CodeRow|K4ZT-CA92|Super Sonic doesn't lose rings with time.}}
 +
{{CodeRow|RE8A-A60G|Level select menu enabled.}}
 +
{{CodeRow|2VAT-BCRA|Start most levels with some rings (1 player game only).}}
 +
}}
 +
 
 +
==== Official codes (REV01)====
 +
{{CodeTable|official=yes|
 +
{{CodeRow|SAST-DJ1A|Rings worth 2 (player 1). }}
 +
{{CodeRow|SAST-DN1A|Rings worth 3 (player 1).}}
 +
{{CodeRow|SAST-DT1A|Rings worth 4 (player 1).}}
 +
{{CodeRow|SAST-DY1A|Rings worth 5 (player 1).}}
 +
{{CodeRow|SAST-D21A|Rings worth 6 (player 1).}}
 +
{{CodeRow|SAST-D61A|Rings worth 7 (player 1).}}
 +
{{CodeRow|SAST-DA1A|Rings worth 8 (player 1).}}
 +
{{CodeRow|AE8A-AAD2|Start with 1 life instead of 3 (player 1).}}
 +
{{CodeRow|AY8A-AAD2|Start with 5 lives (player 1).}}
 +
{{CodeRow|A68A-AAD2|Start with 7 lives (player 1).}}
 +
{{CodeRow|BE8A-AAD2|Start with 9 lives (player 1).}}
 +
{{CodeRow|DE8A-AAD2|Start with 25 lives (player 1).}}
 +
{{CodeRow|GJ8A-AAD2 |Start with 50 lives (player 1).}}
 +
{{CodeRow|KN8A-AAD2|Start with 75 lives (player 1).}}
 +
{{CodeRow|NN8A-AAD2|Start with 99 lives (player 1).}}
 +
{{CodeRow|JW3A-CA4J|Infinite lives (player 1).}}
 +
{{CodeRow|SATA-DJVW|Rings worth 2 (player 2).}}
 +
{{CodeRow|SATA-DNVW|Rings worth 3 (player 2).}}
 +
{{CodeRow|SATA-DTVW|Rings worth 4 (player 2).}}
 +
{{CodeRow|SATA-DYVW|Rings worth 5 (player 2).}}
 +
{{CodeRow|SATA-D2VW|Rings worth 6 (player 2).}}
 +
{{CodeRow|SATA-D6VW|Rings worth 7 (player 2).}}
 +
{{CodeRow|SATA-DAVW|Rings worth 8 (player 2).}}
 +
{{CodeRow|AE8A-AAD8|Start with 1 life instead of 3 (player 2).}}
 +
{{CodeRow|AY8A-AAD8|Start with 5 lives (player 2).}}
 +
{{CodeRow|A68A-AAD8|Start with 7 lives (player 2).}}
 +
{{CodeRow|BE8A-AAD8|Start with 9 lives (player 2).}}
 +
{{CodeRow|DE8A-AAD8|Start with 25 lives (player 2).}}
 +
{{CodeRow|GJ8A-AAD8|Start with 50 lives (player 2).}}
 +
{{CodeRow|KN8A-AAD8|Start with 75 lives (player 2).}}
 +
{{CodeRow|NN8A-AAD8|Start with 99 lives (player 2).}}
 +
{{CodeRow|JXGA-CA7G|Infinite lives (player 2).}}
 +
{{CodeRow|KBVT-CAE2|Jump lower.}}
 +
{{CodeRow|FVVT-CAE2|Jump a little higher.}}
 +
{{CodeRow|EBVT-CAE2|Jump a lot higher (Switch off if you get stuck somewhere or want to go in the water).}}
 +
{{CodeRow|CBVT-CAE2|Jump really high (Switch off if you get stuck somewhere or want to go in the water). }}
 +
{{CodeRow|A02T-CAF8|Sonic stays invincible for a shorter time after getting hit.}}
 +
{{CodeRow|982T-CAF8|Sonic stays invincible for a longer time after getting hit.}}
 +
{{CodeRow|ALTA-CA8N|Sonic becomes invisible and invincible for the rest of the level after getting hit. }}
 +
{{CodeRow|ALTA-CA9J|Once invincible [stars], Sonic stays Invincible for the rest of the level.}}
 +
{{CodeRow|ATTT-CA4W|Sonic doesn't lose rings when hit.}}
 +
{{CodeRow|ATTT-CA5G|Tails doesn't lose rings when hit.}}
 +
{{CodeRow|AH2T-CAH6|Only 1 ring needed instead of 50 to enter special stage.}}
 +
{{CodeRow|SBJA-HJWJ|Rings worth 2 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HNWJ|Rings worth 3 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HTWJ|Rings worth 4 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HYWJ|Rings worth 5 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-H2WJ|Rings worth 6 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-H6WJ|Rings worth 7 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HAWJ|Rings worth 8 in special stages (Sonic only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HJWR|Rings worth 2 in special stage (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HNWR|Rings worth 3 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HTWR|Rings worth 4 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HYWR|Rings worth 5 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-H2WR|Rings worth 6 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-H6WR|Rings worth 7 in special stages (Tails only/Doesn't show on screen). }}
 +
{{CodeRow|SBJA-HAWR|Rings worth 8 in special stages (Tails only/Doesn't show on screen).}}
 +
{{CodeRow|ACZT-CACA|Need 0 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|AGZT-CACA |Need 1 Chaos Emerald to become Super Sonic (Don't grab more than needed). }}
 +
{{CodeRow|ALZT-CACA |Need 2 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|ARZT-CACA |Need 3 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|AWZT-CACA |Need 4 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|A0ZT-CACA |Need 5 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|A4ZT-CACA |Need 6 chaos emeralds to become Super Sonic (Don't grab more than needed).}}
 +
{{CodeRow|AGZT-CACJ + K4ZT-CA9N|Need 1 ring to become Super Sonic, don't lose rings with time.}}
 +
{{CodeRow|A0ZT-CACJ|Need 5 rings to become Super Sonic.}}
 +
{{CodeRow|BLZT-CACJ|Need 10 rings to become Super Sonic.}}
 +
{{CodeRow|DGZT-CACJ|Need 25 rings to become Super Sonic.}}
 +
{{CodeRow|FCZT-CACJ|Need 40 rings to become Super Sonic.}}
 +
{{CodeRow|K4ZT-CA9N|Super Sonic doesn't lose rings with time.}}
 +
{{CodeRow|RE8A-A60W|Level select menu enabled.}}
 +
{{CodeRow|2VAT-BCRN|Start most levels with some rings (1 player game only).}}
 +
{{CodeRow|GJ8A-AA4G|Skip straight to the ending sequence.}}
 +
}}
 +
 
 +
==== Unofficial codes (REV00)====
 +
{{CodeTable|
 +
{{CodeRow|ADFT-8AF6|Regular level music plays when turning into Super Sonic.}}
 +
{{CodeRow|ACLA-ATDR |Access [[Hidden Palace Zone]] by selecting [[Death Egg]] on the Level Select menu (no solid floors, glitched graphics, etc).}}
 +
}}
 +
 
 +
==== Unofficial codes (REV01)====
 +
{{CodeTable|
 +
{{CodeRow|ACZT-CACA|Become Super Sonic With 0 Emeralds.}}
 +
{{CodeRow|ADFT-8AF6|Regular level music plays when turning into Super Sonic.}}
 +
{{CodeRow|982T-C9F8|Keep flashing after hit/Invincible (If you have rings).}}
 +
{{CodeRow|ACLA-ATD4|Access Hidden Palace Zone by selecting Death Egg on the Level Select menu (no solid floors, glitched graphics, etc).}}
 +
{{CodeRow|ACLA-AECY|Access [[Wood Zone]] by selecting [[Emerald Hill Zone]] on the Stage Select screen. (Buggy, pallete-swapped Emerald Hill Zone).}}
 +
}}
 +
 
 +
===[[Action Replay (Mega Drive)|Action Replay]]===
 +
Due to the fact that Pro Action Replay Effects RAM and that RAM is the same regardless of the game revision there is no need for version specific codes. These codes should work in all versions.
 +
====Unofficial codes====
 +
{{CodeTable|
 +
{{CodeRow|FFFE12:0009|Infinite Lives.}}
 +
{{CodeRow|FFFE20:00C8|Infinite Rings.}}
 +
{{CodeRow|FFB030:00FF|Invincibility For Sonic ([[Enemies]] Can't Touch You/Can't collect Rings).}}
 +
{{CodeRow|FFB06A:01|Invincibility For Tails (Always Have Shield).}}
 +
{{CodeRow|FFB070:00FF|Invincibility For Tails (Enemies Can't Touch You).}}
 +
{{CodeRow|FFB028:FA|Infinite Time Underwater For Sonic.}}
 +
{{CodeRow|FFB068:FA|Infinite Time Underwater For Tails.}}
 +
{{CodeRow|FFF761:6410|Sonic has Super Speed.}}
 +
{{CodeRow|FFFEC1:6410|Tails has Super Speed.}}
 +
{{CodeRow|FFFFB1:07|Enable Super Sonic (All [[Chaos Emeralds]] Collected).}}
 +
{{CodeRow|FFB02B:01|Always have Shield.}}
 +
{{CodeRow|FFFE19:01|Play As Super Sonic (No Powers).}}
 +
{{CodeRow|FFF711:??|HUD Display Modifier (00: Off, 01: On).}}
 +
{{CodeRow|FFFFFA:0100|Enable Debug Mode.}}
 +
{{CodeRow|FFFFD0:0100|Enable Stage Select ({{A}}+{{start}} on Title Screen).}}
 +
{{CodeRow|FFFE10:XXYY|Stage/Act Modifier (XX: Zone, YY: Level).
 +
*00 - Emerald Hill
 +
*04 - Metropolis
 +
*06 - Wing Fortress
 +
*07 - Hill Top
 +
*08 - Hidden Palace (!)
 +
*0A - Oil Ocean
 +
*0B - Mystic Cave
 +
*0C - Casino Night
 +
*0D - Chemical Plant
 +
*0E - Death Egg
 +
*0F - Aquatic Ruin
 +
*10 - Sky Chase}}
 +
{{CodeRow|FFB461:01|Defeat Final Stage Bosses With 1 Hit.}}
 +
{{CodeRow|FFB521:01|Defeat Stage 1 Robotnik With 1 Hit.}}
 +
{{CodeRow|FFB621:01|Defeat Stage 2 Robotnik With 1 Hit.}}
 +
{{CodeRow|FFB721:01|Defeat Stage 3 Robotnik With 1 Hit.}}
 +
{{CodeRow|FFB821:01|Defeat Stage 4 Robotnik With 1 Hit.}}
 +
{{CodeRow|FFB921:01|Defeat Stage 5 Robotnik With 1 Hit.}}
 +
{{CodeRow|FFBA21:01|Defeat Stage 6 Robotnik With 1 Hit.}}
 +
{{CodeRow|FFBB21:01|Defeat Stage 7 Robotnik With 1 Hit.}}
 +
{{CodeRow|FFBC21:01|Defeat Stage 8 Robotnik With 1 Hit.}}
 +
}}
 +
 
 +
==== Unofficial codes (user found)====
 +
{{CodeTable|
 +
{{CodeRow|FFFE12:999D|Start wing fortress(Not sure about others) with 53(i guess) lives. Super Sonic mode Presents.}}
 +
{{CodeRow|016398:0100|Very short jump height.}}
 +
{{CodeRow|FFB03A:11C0|Sonic Generations spindash (partially breaks the game, dying softlocks the game)}}
 +
{{CodeRow|004476:00XX|Player slot ID (When playing as Sonic & Tails). XX is the ID (Example: 004476:0025 changes Sonic to a ring).}}
 +
{{CodeRow|00449A:00XX|Sidekick slot ID (When playing as Sonic & Tails). XX is the ID.}}
 +
}}
  
Commentary found in the ''[[Sonic Jam]]'' strategy guide reveals that the level order could have been even more different. It states that [[Chemical Plant Zone]] was meant to be the 10th zone back when the game was planned as an 18 zone game.
+
If you want to make your own codes, see [[SCHG:Sonic 2/RAM Editing|here]]. The format to edit those RAM values with PAR codes is this: FFXXXX:YY FF is FF, XXXX is the position of the data in RAM in four hexadecimal digits and YY is the value you want to put in in two or four hexadecimal digits. Remamber to convert your decimal value to [[sega:Hexadecimal|hexadecimal]] first. For 2 Byte/16 bit values, put four digits in YY. If you need to enter values with four Bytes, you have to split it into two 2 Byte codes.
  
==2013 Game==
+
==References==
[[Category:Game secrets|Sonic the Hedgehog 2 (16-bit)]]
+
<references/>
  
 
{{S2MDOmni}}
 
{{S2MDOmni}}

Revision as of 13:58, 16 January 2020

Back to: Sonic the Hedgehog 2 (16-bit).

Level select

S2 level select.png

Play songs 19, 65, 09, 17 on the options screen, then hold A+Start on title screen.

Edit mode

Sonic2 MD DebugMode.png

From the level select menu, play songs 01, 09, 09, 02, 01, 01, 02, 04 (1992-11-24 - the worldwide launch date of Sonic 2). A Ring sound should trigger. Select a Zone and hold A until the title card disappears.

Edit mode does not work when playing as Tails in this game, even though the counters for debug mode are still intact here.

Night mode

Sonic2 MD NightMode.png

After enabling edit mode, select a level on the level select screen and hold C+Start until the title card disappears.

Get all Chaos Emeralds

From the level select menu, play songs 04, 01, 02, 06 on the sound test and a Chaos Emerald sound effect will trigger. This immediately gives the player all seven Chaos Emeralds, enabling Super Sonic.

Swap Tails for Miles

Sonic2 MD Comparison OptionsJP.png

Press Up Down Down Down Up at the title screen. This will cause all instances of "Tails" to change to "Miles", except in the Japanese version where the reverse will happen. This also toggles the trademark symbols on the Sega logo and the title screen.

14 continues

Sonic2 MD 14Continues.png

Play songs 01, 01, 02, 04 on the options screen. An incorrect sound command is issued, causing Oil Ocean Zone music to continue playing until a reset.

Unused content

Art

Art Description
An animation very similar to one used in Wing Fortress Zone when Sonic grabs the panels on the side of the ship. However, this is vertical. Its frame IDs are 52 and 53.
An alternate death frame for Sonic, defined in animation 16 with a frame ID of 5E. This returns from (and is also unused in) Sonic the Hedgehog.
Sonic2 MD Sprite CPZSirenLights.gif
Unused decorative objects for Chemical Plant Zone, stored at 0x0383-0x0393 in VRAM. These can be placed in the iOS/Android 2013 version's debug mode.
Spr cpzboss.gif
An animation for Water Eggman which shows Dr. Eggman dropping chemicals on himself. This animation has been around since the Nick Arcade prototype, but it was never implemented. A fix to implement the lost animation can be found here.
Sonic2 MD Sprite OOZSpringHolder.png
A holder for Oil Ocean Zone's ball and spring object (see below). This appeared in the Simon Wai prototype, and is still loaded into VRAM in the final game.
An unused animation for Aquis spitting up oil, along with an oil spray.
Balkiry2.png
Unused frame of the Balkiry badnik with landing gear. It's possible that they were originally intended to take off from the Wing Fortress Zone as it passed by. If a Balkiry is selected in debug mode, this sprite will be seen instead of its flying one.
S2-Turtle.gif
Walking sprites of Tocky, who pops out of the Badniks in Sky Chase Zone. Normally the player will never see this, since the animal never has the opportunity to hit the ground. In order to see it, the player must use debug mode to create and destroy a Badnik while the Wing Fortress passes by. This animation would later make an appearance in Sonic Mania, as Tocky can be found in Titanic Monarch Zone.
S2-Picky.gif
Picky, a returning animal from the original Sonic the Hedgehog, is present in Death Egg Zone. However, there are no Badniks or animal capsules, so he's never seen.
Sonic2-RobotnikLaugh.gif
In Death Egg Zone, getting hit with one or more Rings during the Mecha Sonic battle causes Eggman to laugh. However, this is never actually seen outside of debug mode because the Zone has no Rings. In the 2013 mobile remake, this animation can be seen normally if the player dies during the fight. In 3D Sonic the Hedgehog 2 it can also be seen if the player is hurt by Mecha Sonic if the Ring Keeper mode is on.
HPZiconS2.png
Level Select icon for Hidden Palace Zone, which never made it into the final game. The art however, is present in Sonic 3's level select. Pro Action Replay code 0096D8:0303 will cause it to replace the Emerald Hill Zone icon in the Stage Select.

Objects

Art Description
S2 static monitor.png
A static or blank monitor which harms the player when broken. Never seen in-game. To see it, a monitor's subtype should be set to 00.
A hovering platform for Chemical Plant Zone that has been around since the Nick Arcade prototype. Every 1024 frames, it will slowly rise up for 128 frames, float in the air, then come back down 128 frames later. The amount of time it floats in the air is 128*(lower four bits of subtype) frames. The upper four bits can be used to offset when it starts to rise in the air. Its object ID is $0C.
Aquatic ruin door.png
Unused door barriers from Aquatic Ruin Zone, which function like the door barriers found in other Zones. This can be placed with debug mode.
Sonic2-mrzobject.png
A strange platform made of Rings, placeable using debug mode in Mystic Cave Zone. When placed, this object will slowly swing in an anti-clockwise direction and can be stood on. This object has existed since the Simon Wai prototype, and its object ID is $73.
A ball and spring object, which can be placed in Oil Ocean Zone via debug mode. If a button is placed near it and pressed, the ball will pop out and start rolling in whichever direction Sonic was facing when the object was placed. It seems this object would have been used to cross something, as it can be stood upon, much like the ball object that appeared in early versions of Sonic the Hedgehog. It does not collide with breakable floors or elevators, and it will go up slopes and even vertical walls without slowing or stopping. It is used in the Simon Wai and Aug 21st Alpha prototypes. Its object ID is $46.
Sonic2Alpha MD Sprite OOZTube.png
Horizontal versions of the breakable pressure stopper in Oil Ocean Zone exist. These can be jumped on, but they will send Sonic and Tails left or right rather than up. Once Sonic is travelling, the player can't make him stop unless he collides with an object - even in edit mode the player will continue to travel. This would have been used in the Simon Wai layout of the Zone, but has no purpose in the final layout.
Although very similar to the small platforms used in Metropolis Zone, this platform behaves strangely, usually rising at an angle. Its object ID is $6C.
Sonic2-giantlaser.gif
Large laser shooting through a spinning platform in Wing Fortress Zone. If the sub-ID of the spinning platforms has bit 02 of their subtype set but not 04, they will become this object. This object can be placed with debug mode, where it oddly appears before the used platform in the object list. Its object ID is $B7.
Sonic2-wfz-spinnything2.gif
Weird spinning pole in Wing Fortress Zone that acts like a Badnik - the player can destroy it, and it can hurt them, but it doesn't actually move. Its object ID is $BF, and it is placeable with debug mode.
The emerald-shaped object that was used in Hidden Palace Zone to block off a tube. The graphics are long gone, but the code is still there. It's a simple solid indestructible object and its coding hasn't changed since the Nick Arcade prototype. Its object ID is $12.
The waterfall object from Hidden Palace Zone, which is also left over. Again, the graphics no longer exist in the ROM. Its height is equal to 16*(lower five bits of subtype)+16 pixels. Placing one with a subtype greater than 17 will spawn garbage objects on the right. Its object ID is $13.
The spinning log spikes from Sonic the Hedgehog's Green Hill Zone. Unfortunately, the graphics have been deleted, but the coding is intact. Its object ID is $17.

Score tally

Sonic2UnusedScoreTally.png

This configuration of the score tally is unused but was meant for levels with a single Act (Sky Chase Zone, etc). It can be made to appear by using debug mode and placing, then breaking a capsule.

Audio

Music

In the sound test, song $10 is a unused song. This has been established to be the music meant for Hidden Palace Zone.

Sound effects

Sounds not used anywhere in the game can be heard in the sound test, some of which are leftovers from the original Sonic the Hedgehog.

Audio ID Description
Sonic the Hedgehog leftovers
29 The sound for touching the R, Up, and Down Special Stage blocks.
31 Scrap Brain Zone electricity.
3A The sound for touching the colour-changing diamonds in the Special Stage.
43 The sound for entering Giant Rings at the end of an Act.
47 The chain pulling sound from Marble Zone.
49 The bonus point tags found at the end of an Act.
Other sounds
38 Sounds similar to the sound of spikes popping up. Also unused in Sonic 1.
51 Unknown. Sounds like something popping or skidding on the ground.
52 A low siren, similar to $53 which is used in the 2-Player mode.
68 Sounds like a slightly shorter version of Mystic Cave Zone's bridges stopping in place ($69).

Level slots

Like its predecessor, Sonic 2 on the Mega Drive lays out its levels in a different order internally to how the player sees them when playing through the game. It gives some clues as to what the original progression looked like, and the differences are quite significant.

The internal level order can be seen by using Pro Action Replay code (FFFE10:??00), substituting the question marks with the hexadecimal values for the level slots described in the table below and then attempting to enter any level (any number past 10 crashes the game). Metropolis Zone covers two level slots as it has three Acts.

Level slot Level name In-game order Comments
00 Emerald Hill Zone 01
01 Unknown Plays Emerald Hill Zone's music.
02 Wood Zone Scrapped Palette is all that remains. Plays Metropolis Zone's music.
03 Unknown Plays Oil Ocean Zone's music.
04 Metropolis Zone 08
05 Metropolis Zone (Act 3) 09
06 Wing Fortress Zone 11
07 Hill Top Zone 05
08 Hidden Palace Zone Scrapped Palette and object/ring locations remain. Plays unused track #10.
09 Unknown Plays Sky Chase Zone's music.
100A Oil Ocean Zone 07
110B Mystic Cave Zone 06
120C Casino Night Zone 04
130D Chemical Plant Zone 02
140E Death Egg Zone 12 Occupied by Genocide City Zone in prototypes.
150F Aquatic Ruin Zone 03
1610 Sky Chase Zone 10

This order is mirrored (with empty slots cut out) by some prototype level select screens. All empty slots are fundamentally broken, loading varying amounts of graphics data from Emerald Hill Zone (depending on the build).

Three slots in the game remain empty in all versions of Sonic 2 (save for the very early Nick Arcade prototype which is using the Sonic 1 level order). There has been much speculation over the years about what these slots were reserved for (if anything) - possible candidates include Brenda Ross's "desert" and "winter" zones which were thought to be at least partially complete, or possibly Genocide City Zone before it was transformed into Metropolis Zone Act 3. The team are known to have explored many level ideas during development, most of which did not make it past the design stage.

Commentary found in the Sonic Jam strategy guide reveals that the level order could have been even more different. It states that Chemical Plant Zone was meant to be the 10th Zone back when the game was planned as an 18-Zone game.

Inaccessible Rings

There are some levels that have Rings in places that can't be reached normally. This makes getting a Perfect Bonus in these stages impossible.[1]

Screenshot Level Approximate coordinates Description
Sonic2AquaticRuinZone-Rings.png
Aquatic Ruin Zone Act 2 1FA90626 Two horizontally lined rings.
Sonic2CasinoNightZone-Rings.png
Casino Night Zone Act 2 027F00F8 Two groups of seven rings. These are right at the start of the level but cannot be reached with a jump or using nearby objects.
Sonic2MysticCaveZone-Rings1.png
Sonic2MysticCaveZone-Rings2.png
Mystic Cave Zone Act 2 16050156
1712016D
Three horizontally lined rings, and a nearby curve of rings, similar to ones found near swings. Both sets of rings are found in the ceiling.
Sonic2OilOceanZone-Rings1.png
Sonic2OilOceanZone-Rings2.png
Sonic2OilOceanZone-Rings3.png
Oil Ocean Zone Act 2 1A0001F8
0B9F03B0
1245021C
Three horizontally lined rings, close to the launcher and invincibility monitor. Three vertically lined rings stuck in a block which prohibits access to them. Rings in a upside down v shape pattern. They are stuck inside the wall, thus unaccessable.
Sonic2MetropolisZone-Rings.png
Metropolis Zone Act 2 02C0043F Three slanted rings, in the floor that has a ten-ring monitor and a cog close-by.

Scrapped Zone remnants

There are small remnants of Hidden Palace Zone, Wood Zone, Genocide City Zone, and Dust Hill Zone in the final game. See the aforementioned level pages for more information.

Cheat device codes

These are cheat codes that can only be used with game enhancer devices. Support for these codes is available in most emulators. There are two versions of this game. If one code doesn't work on your game, then try the other.

Game Genie

Official codes (REV00)

Code Effect Reference
SATA-DJTJ Rings worth 2 (player 1).
SATA-DNTJ Rings worth 3 (player 1).
SATA-DTTJ Rings worth 4 (player 1).
SATA-DYTJ Rings worth 5 (player 1).
SATA-D2TJ Rings worth 6 (player 1).
SATA-D6TJ Rings worth 7 (player 1).
SATA-DATJ Rings worth 8 (player 1).
AE8A-AADN Start with 1 life instead of 3 (player 1).
AY8A-AADN Start with 5 lives (player 1).
A68A-AADN Start with 7 lives (player 1).
BE8A-AADN Start with 9 lives (player 1).
DE8A-AADN Start with 25 lives (player 1).
GJ8A-AADN Start with 50 lives (player 1).
KN8A-AADN Start with 75 lives (player 1).
NN8A-AADN Start with 99 lives (player 1).
JW3A-CA4Y Infinite lives (player 1).
SATA-DJW8 Rings worth 2 (player 2).
SATA-DNW8 Rings worth 3 (player 2).
SATA-DTW8 Rings worth 4 (player 2).
SATA-DYW8 Rings worth 5 (player 2).
SATA-D2W8 Rings worth 6 (player 2).
SATA-D6W8 Rings worth 7 (player 2).
SATA-DAW8 Rings worth 8 (player 2).
AE8A-AADW Start with 1 life instead of 3 (player 2).
AY8A-AADW Start with 5 lives (player 2).
A68A-AADW Start with 7 lives (player 2).
BE8A-AADW Start with 9 lives (player 2).
DE8A-AADW Start with 25 lives (player 2).
GJ8A-AADW Start with 50 lives (player 2).
KN8A-AADW Start with 75 lives (player 2).
NN8A-AADW Start with 99 lives (player 2).
JXGA-CA7W Infinite lives (player 2).
KBVT-CAE2 Jump lower.
FVVT-CAE2 Jump a little higher.
EBVT-CAE2 Jump a lot higher (Switch off if you get stuck somewhere or want to go in the water).
CBVT-CAE2 Jump really high (Switch off if you get stuck somewhere or want to go in the water).
A02T-CAGL Sonic stays invincible for a shorter time after getting hit.
982T-CAGL Sonic stays invincible for a longer time after getting hit.
ALTA-CA82 Sonic becomes invisible and invincible for the rest of the level after getting hit.
ALTA-CA9Y Once invincible [stars], Sonic stays Invincible for the rest of the level.
ATTT-CA58 Sonic doesn't lose rings when hit.
ATTT-CA6W Tails doesn't lose rings when hit.
ATTT-CA6W Only 1 ring needed instead of 50 to enter special stage.
SBJA-HJV2 Rings worth 2 in special stages (Sonic only/Doesn't show on screen).
SBJA-HNV2 Rings worth 3 in special stages (Sonic only/Doesn't show on screen).
SBJA-HTV2 Rings worth 4 in special stages (Sonic only/Doesn't show on screen).
SBJA-HYV2 Rings worth 5 in special stages (Sonic only/Doesn't show on screen).
SBJA-H2V2 Rings worth 6 in special stages (Sonic only/Doesn't show on screen).
SBJA-H6V2 Rings worth 7 in special stages (Sonic only/Doesn't show on screen).
SBJA-HAV2 Rings worth 8 in special stages (Sonic only/Doesn't show on screen).
SBJA-HJV8 Rings worth 2 in special stage (Tails only/Doesn't show on screen).
SBJA-HNV8 Rings worth 3 in special stages (Tails only/Doesn't show on screen).
SBJA-HTV8 Rings worth 4 in special stages (Tails only/Doesn't show on screen).
SBJA-HYV8 Rings worth 5 in special stages (Tails only/Doesn't show on screen).
SBJA-H2V8 Rings worth 6 in special stages (Tails only/Doesn't show on screen).
SBJA-H6V8 Rings worth 7 in special stages (Tails only/Doesn't show on screen).
SBJA-HAV8 Rings worth 8 in special stages (Tails only/Doesn't show on screen).
ACZT-CACN Need 0 chaos emeralds to become Super Sonic (Don't grab more than needed).
AGZT-CACN Need 1 Chaos Emerald to become Super Sonic (Don't grab more than needed).
ALZT-CACN Need 2 chaos emeralds to become Super Sonic (Don't grab more than needed).
ARZT-CACN Need 3 chaos emeralds to become Super Sonic (Don't grab more than needed).
AWZT-CACN Need 4 chaos emeralds to become Super Sonic (Don't grab more than needed).
A0ZT-CACN Need 5 chaos emeralds to become Super Sonic (Don't grab more than needed).
A4ZT-CACN Need 6 chaos emeralds to become Super Sonic (Don't grab more than needed).
AGZT-CACY + K4ZT-CA92 Need 1 ring to become Super Sonic, don't lose rings with time.
A0ZT-CACY Need 5 rings to become Super Sonic.
BLZT-CACY Need 10 rings to become Super Sonic.
DGZT-CACY Need 25 rings to become Super Sonic.
FCZT-CACY Need 40 rings to become Super Sonic.
K4ZT-CA92 Super Sonic doesn't lose rings with time.
RE8A-A60G Level select menu enabled.
2VAT-BCRA Start most levels with some rings (1 player game only).

Official codes (REV01)

Code Effect Reference
SAST-DJ1A Rings worth 2 (player 1).
SAST-DN1A Rings worth 3 (player 1).
SAST-DT1A Rings worth 4 (player 1).
SAST-DY1A Rings worth 5 (player 1).
SAST-D21A Rings worth 6 (player 1).
SAST-D61A Rings worth 7 (player 1).
SAST-DA1A Rings worth 8 (player 1).
AE8A-AAD2 Start with 1 life instead of 3 (player 1).
AY8A-AAD2 Start with 5 lives (player 1).
A68A-AAD2 Start with 7 lives (player 1).
BE8A-AAD2 Start with 9 lives (player 1).
DE8A-AAD2 Start with 25 lives (player 1).
GJ8A-AAD2 Start with 50 lives (player 1).
KN8A-AAD2 Start with 75 lives (player 1).
NN8A-AAD2 Start with 99 lives (player 1).
JW3A-CA4J Infinite lives (player 1).
SATA-DJVW Rings worth 2 (player 2).
SATA-DNVW Rings worth 3 (player 2).
SATA-DTVW Rings worth 4 (player 2).
SATA-DYVW Rings worth 5 (player 2).
SATA-D2VW Rings worth 6 (player 2).
SATA-D6VW Rings worth 7 (player 2).
SATA-DAVW Rings worth 8 (player 2).
AE8A-AAD8 Start with 1 life instead of 3 (player 2).
AY8A-AAD8 Start with 5 lives (player 2).
A68A-AAD8 Start with 7 lives (player 2).
BE8A-AAD8 Start with 9 lives (player 2).
DE8A-AAD8 Start with 25 lives (player 2).
GJ8A-AAD8 Start with 50 lives (player 2).
KN8A-AAD8 Start with 75 lives (player 2).
NN8A-AAD8 Start with 99 lives (player 2).
JXGA-CA7G Infinite lives (player 2).
KBVT-CAE2 Jump lower.
FVVT-CAE2 Jump a little higher.
EBVT-CAE2 Jump a lot higher (Switch off if you get stuck somewhere or want to go in the water).
CBVT-CAE2 Jump really high (Switch off if you get stuck somewhere or want to go in the water).
A02T-CAF8 Sonic stays invincible for a shorter time after getting hit.
982T-CAF8 Sonic stays invincible for a longer time after getting hit.
ALTA-CA8N Sonic becomes invisible and invincible for the rest of the level after getting hit.
ALTA-CA9J Once invincible [stars], Sonic stays Invincible for the rest of the level.
ATTT-CA4W Sonic doesn't lose rings when hit.
ATTT-CA5G Tails doesn't lose rings when hit.
AH2T-CAH6 Only 1 ring needed instead of 50 to enter special stage.
SBJA-HJWJ Rings worth 2 in special stages (Sonic only/Doesn't show on screen).
SBJA-HNWJ Rings worth 3 in special stages (Sonic only/Doesn't show on screen).
SBJA-HTWJ Rings worth 4 in special stages (Sonic only/Doesn't show on screen).
SBJA-HYWJ Rings worth 5 in special stages (Sonic only/Doesn't show on screen).
SBJA-H2WJ Rings worth 6 in special stages (Sonic only/Doesn't show on screen).
SBJA-H6WJ Rings worth 7 in special stages (Sonic only/Doesn't show on screen).
SBJA-HAWJ Rings worth 8 in special stages (Sonic only/Doesn't show on screen).
SBJA-HJWR Rings worth 2 in special stage (Tails only/Doesn't show on screen).
SBJA-HNWR Rings worth 3 in special stages (Tails only/Doesn't show on screen).
SBJA-HTWR Rings worth 4 in special stages (Tails only/Doesn't show on screen).
SBJA-HYWR Rings worth 5 in special stages (Tails only/Doesn't show on screen).
SBJA-H2WR Rings worth 6 in special stages (Tails only/Doesn't show on screen).
SBJA-H6WR Rings worth 7 in special stages (Tails only/Doesn't show on screen).
SBJA-HAWR Rings worth 8 in special stages (Tails only/Doesn't show on screen).
ACZT-CACA Need 0 chaos emeralds to become Super Sonic (Don't grab more than needed).
AGZT-CACA Need 1 Chaos Emerald to become Super Sonic (Don't grab more than needed).
ALZT-CACA Need 2 chaos emeralds to become Super Sonic (Don't grab more than needed).
ARZT-CACA Need 3 chaos emeralds to become Super Sonic (Don't grab more than needed).
AWZT-CACA Need 4 chaos emeralds to become Super Sonic (Don't grab more than needed).
A0ZT-CACA Need 5 chaos emeralds to become Super Sonic (Don't grab more than needed).
A4ZT-CACA Need 6 chaos emeralds to become Super Sonic (Don't grab more than needed).
AGZT-CACJ + K4ZT-CA9N Need 1 ring to become Super Sonic, don't lose rings with time.
A0ZT-CACJ Need 5 rings to become Super Sonic.
BLZT-CACJ Need 10 rings to become Super Sonic.
DGZT-CACJ Need 25 rings to become Super Sonic.
FCZT-CACJ Need 40 rings to become Super Sonic.
K4ZT-CA9N Super Sonic doesn't lose rings with time.
RE8A-A60W Level select menu enabled.
2VAT-BCRN Start most levels with some rings (1 player game only).
GJ8A-AA4G Skip straight to the ending sequence.

Unofficial codes (REV00)

Code Effect
ADFT-8AF6 Regular level music plays when turning into Super Sonic.
ACLA-ATDR Access Hidden Palace Zone by selecting Death Egg on the Level Select menu (no solid floors, glitched graphics, etc).

Unofficial codes (REV01)

Code Effect
ACZT-CACA Become Super Sonic With 0 Emeralds.
ADFT-8AF6 Regular level music plays when turning into Super Sonic.
982T-C9F8 Keep flashing after hit/Invincible (If you have rings).
ACLA-ATD4 Access Hidden Palace Zone by selecting Death Egg on the Level Select menu (no solid floors, glitched graphics, etc).
ACLA-AECY Access Wood Zone by selecting Emerald Hill Zone on the Stage Select screen. (Buggy, pallete-swapped Emerald Hill Zone).

Action Replay

Due to the fact that Pro Action Replay Effects RAM and that RAM is the same regardless of the game revision there is no need for version specific codes. These codes should work in all versions.

Unofficial codes

Code Effect
FFFE12:0009 Infinite Lives.
FFFE20:00C8 Infinite Rings.
FFB030:00FF Invincibility For Sonic (Enemies Can't Touch You/Can't collect Rings).
FFB06A:01 Invincibility For Tails (Always Have Shield).
FFB070:00FF Invincibility For Tails (Enemies Can't Touch You).
FFB028:FA Infinite Time Underwater For Sonic.
FFB068:FA Infinite Time Underwater For Tails.
FFF761:6410 Sonic has Super Speed.
FFFEC1:6410 Tails has Super Speed.
FFFFB1:07 Enable Super Sonic (All Chaos Emeralds Collected).
FFB02B:01 Always have Shield.
FFFE19:01 Play As Super Sonic (No Powers).
FFF711:?? HUD Display Modifier (00: Off, 01: On).
FFFFFA:0100 Enable Debug Mode.
FFFFD0:0100 Enable Stage Select (A+Start on Title Screen).
FFFE10:XXYY Stage/Act Modifier (XX: Zone, YY: Level).
  • 00 - Emerald Hill
  • 04 - Metropolis
  • 06 - Wing Fortress
  • 07 - Hill Top
  • 08 - Hidden Palace (!)
  • 0A - Oil Ocean
  • 0B - Mystic Cave
  • 0C - Casino Night
  • 0D - Chemical Plant
  • 0E - Death Egg
  • 0F - Aquatic Ruin
  • 10 - Sky Chase
FFB461:01 Defeat Final Stage Bosses With 1 Hit.
FFB521:01 Defeat Stage 1 Robotnik With 1 Hit.
FFB621:01 Defeat Stage 2 Robotnik With 1 Hit.
FFB721:01 Defeat Stage 3 Robotnik With 1 Hit.
FFB821:01 Defeat Stage 4 Robotnik With 1 Hit.
FFB921:01 Defeat Stage 5 Robotnik With 1 Hit.
FFBA21:01 Defeat Stage 6 Robotnik With 1 Hit.
FFBB21:01 Defeat Stage 7 Robotnik With 1 Hit.
FFBC21:01 Defeat Stage 8 Robotnik With 1 Hit.

Unofficial codes (user found)

Code Effect
FFFE12:999D Start wing fortress(Not sure about others) with 53(i guess) lives. Super Sonic mode Presents.
016398:0100 Very short jump height.
FFB03A:11C0 Sonic Generations spindash (partially breaks the game, dying softlocks the game)
004476:00XX Player slot ID (When playing as Sonic & Tails). XX is the ID (Example: 004476:0025 changes Sonic to a ring).
00449A:00XX Sidekick slot ID (When playing as Sonic & Tails). XX is the ID.

If you want to make your own codes, see here. The format to edit those RAM values with PAR codes is this: FFXXXX:YY FF is FF, XXXX is the position of the data in RAM in four hexadecimal digits and YY is the value you want to put in in two or four hexadecimal digits. Remamber to convert your decimal value to hexadecimal first. For 2 Byte/16 bit values, put four digits in YY. If you need to enter values with four Bytes, you have to split it into two 2 Byte codes.

References


Sonic the Hedgehog 2 (16-bit)
Sonic2 title.png

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