Actions

Sonic & Knuckles/Hidden content

From Sonic Retro

Back to: Sonic & Knuckles.
Clock.svg This article is outdated.
Due to changing events, this article is either no longer correct or needs information added to it to make it complete. Please update it so that it meets current knowledge.

Level select

SK level select.png

While in Mushroom Hill Zone, jump on to one of the pulley systems, then press Left Left Left Right Right Right Up Up Up. A Ring sound will confirm correct entry. Press Start, then A to return to the title screen. Press A+Start to go to the Level Select screen.

Though the Sonic the Hedgehog 3 Zones are listed, they are not available unless Sonic 3 is locked-on; selecting any of them will load Mushroom Hill Zone Act 1. The player's character can be chosen by pressing C, though selecting 00 or 02 (normally associated with Tails) will override the player's character to Sonic.

Debug mode

Notavailable.svg

Contrary to popular belief, there IS a debug mode available for this game. Sonic the Hedgehog 3 & Knuckles runs on the codebase of Sonic & Knuckles which has a separate check to enable a debug mode cheat code in place of the level select code in Mushroom Hill when Sonic 3 is locked on. To use debug mode purely in Sonic and Knuckles, the player needs to overwrite the memory of the game while a Sonic 3 cartridge or ROM is locked on. Simply start up Sonic 3 & Knuckles, unlock the level select and debug mode codes for that game and then highlight any level in the Sound Test, hold A, press Start, and release A when Sonic appears. Switch to an "S" Monitor, and paste a big amount of monitors until sprites begin to flicker. Then revert back to Sonic, and Spin Dash or jump straight into the monitors. Due to how the game loads its art, the game will break, crash or reset to demo mode. If the game has not crashed yet, press Start, and then press A if necessary. The game may ignore any flags for a Sonic 3 cartridge being detected and it will boot up into Sonic & Knuckles mode, redirecting the player to the Sonic & Knuckles title screen. Choose any character, hold A then press Start to go to the level select screen. Highlight any level, hold A, then press Start.

During gameplay:

  • Press A to reverse gravity when in normal mode.
  • Press C+B to cycle through all mapping frames of the character when in normal mode.
  • Press B to toggle normal and debug mode.
    • Press A to advance forward through the debug object list.
    • Press A+C to advance backwards through the debug object list.
    • Press C to place the selected object at the current coordinates.
  • During pause press A to fade to black and restart from the SEGA screen.
  • During pause press and hold B to enable slow-motion (this proceeds at half-speed for as long as the B button is held down).
  • During pause press C to advance one frame.
  • Current coordinates are designated by the top line of hex digits in the HUD.
  • Viewport coordinates are designated by the bottom line of hex digits in the HUD.

Eighth Special Stage

SonicandKnuckles MD SpecialStage 8 Start.png
S&KSS8.png

If Sound Test is enabled, and any of the "Special Stage" options is selected, Sonic or Knuckles is taken to the first Special Stage. The end of it however, spawns a yellow Super Emerald. This is when the special stage is marked as clear, but the normal Chaos Emerald amount doesn't rise. The Super Emerald amount will rise, but it has pretty much no effect due to Super Emeralds being unobtainable in Sonic & Knuckles alone. This bug will allow access to a hidden Special Stage and allow for the 8th Emerald to be collected once the other six have, though.

It is also possible to access this Special Stage by enabling debug mode above, then setting the Sound Test selection to 07 and pressing A+Start while selecting any of the Special Stage options.

Hidden area of Hidden Palace Zone

Sonic3kmonitors.png
SnK HPZ SecretAreaRight.png

When using edit mode in Hidden Palace Zone, an area above and to the left of Sonic's fight with Knuckles contains a selection of monitors; six on the left, and three on the right. In Sonic 3 & Knuckles, Tails can fly up to this area.

It has been suggested that these could have been placed here so that clean screenshots could be taken for the Japanese manual. The manual clearly shows Sonic bubble bouncing in Hidden Palace, despite no Water Shields being available through normal playMedia:S&K MD JP manual.pdf[1]Media:S&K MD JP manual.pdf[2].

Bow to Knuckles

SonicandKnuckles MD SSZBow.png

After Knuckles has let the player across in Sky Sanctuary Zone, if the player stands in a certain spot and bow (duck) with Down, as is customary in Japan, Knuckles turns around and gives a "get going" gesture.

Unused content

Art

Art Description
Vertical hanging sprites for Knuckles.
A monochrome death sprite for Knuckles.
An unused, slightly different version of Hey Ho.
An unused frame for Eggman for use with the Hang Mobile when attacking. It doesn't appear due to a programming oversight.
An unused piece of the Egg Golem boss.
A jumping frame for Eggrobo.
SnKSSJackpot.png
Slot machine image for Super Sonic, intended for the Slot Machine Bonus Stage.
SnKSball.gif
A flashing S gumball. One could presume it has something to do with Super Sonic.
SnKPalmtree.jpg
Unseen palm tree graphics. Although these tiles are used in both Sonic 3 and Sonic 3 & Knuckles in the introduction to Angel Island Zone, they are hidden behind leaf sprites. This is how it looks with the sprites layer disabled:
SecretPalmtree.png

Objects

Placeable in edit mode

Art Description
A lava stepping stone for the second Act of Lava Reef Zone. Similar objects exist in Act 1, but this unique art for Act 2 is never seen.
SnKplatform.png
A platform for the Glowing Spheres Bonus Stage.
SnKFball.png
"F" gumball, placeable in Glowing Spheres Bonus Stage. When collected it makes the same noise as a Bumper Ball, but it doesn't do anything.

Others

Art Description
SnKHoloscreen.gif
A rotating holograph of the Death Egg. It can be found by hex-editing a savestate of Death Egg Act 2. At address A500 replace 01 with E5 and the most northwestern piece will change to this. Thanks to Gold for finding this.
A solid block that uses art for the slot in the Slot Machine Bonus Stage.

Tails

Tails in S&K.png

Tails is playable in the game through hacking. Unfortunately, most of his sprites are missing. A savestate (info) (50 kB) of Tails in Sonic & Knuckles is available. If the PAR code FFFF09:02 is used in Sonic & Knuckles, Tails will be usable, but just about every sprite of his, except the transformation sprite, will be missing, basically rendering him invisible (unlike when a savestate is used; a different, glitchy sprite is used in place of Tails's original one). However, his sprites used at the end of Sky Sanctuary Zone to run around the collapsing pillar are actually stored in the Sonic & Knuckles' ROM and therefore are visible. The same sprites are used also in the same context in Lava Reef Zone.

Misplaced objects

Flying Battery Zone Act 1

Sonic&Knuckles MD FBZ1 MisplacedSprings.png

There are two yellow springs buried in the ground near the first giant purple tube.

Death Egg Zone Act 1

Sonic&Knuckles MD DEZ1 MisplacedRings.png

There are three Rings placed in the floor under the first black anti-gravity orb. It is possible to collect these Rings by returning to this point with a Lightning Shield.

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.

Game Genie

Official Codes, Sonic & Knuckles Alone

Code Description Works in S&K Works in S3K
General codes
AFKT-AAG0 Start with 1 life. Yes No
AKKT-AAG0 Start with 2 lives. Yes No
AVKT-AAG0 Start with 4 lives. Yes No
AZKT-AAG0 Start with 5 lives. Yes No
A7KT-AAG0 Start with 7 lives. Yes No
BFKT-AAG0 Start with 9 lives. Yes No
DFKT-AAG0 Start with 25 lives. Yes No
GKKT-AAG0 Start with 50 lives. Yes No
NPKT-AAG0 Start with 99 lives. Yes No
K2WA-CA4J Infinite lives. Yes Yes

Official Codes, Sonic the Hedgehog 3 Locked-on

Code Description Works in S&K Works in S3K
General codes
AWXT-CA4C Don't lose rings when hit. Yes Yes
HXRT-AA6A Infinite time. Yes Yes
96BA-CAG6 + 98MA-CAF0 Keep elemental shields when hit. Yes Yes
AKVT-AA76 + AMNA-EA24 Keep rings between levels. Yes Yes
RHJA-E60L Bonus round always activated after every checkpoint. Yes Yes
RGSA-A6YY Only 1 blue sphere needed to get a chaos emerald. Yes Yes
ALNA-AACR Rings worth 2 in special stage. Yes Yes
ARNA-AACR Rings worth 3 in special stage. Yes Yes
AWNA-AACR Rings worth 4 in special stage. Yes Yes
A0NA-AACR Rings worth 5 in special stage. Yes Yes
BLNA-AACR Rings worth 10 in special stage. Yes Yes
NTPT-CA50 Rings aren't used up as Super (or Hyper) Sonic/Knuckles. Yes Yes
ACCT-CA2R Can't drown. Yes Yes
Sonic-specific codes
RENT-C6YA Can always double jump (can't use water shield or become Super Sonic). Yes Yes
RENT-C6V6 Can always use Fireball Spin Dash (can't double jump, bounce, or become Super Sonic). Yes Yes
AANA-CNA0 Jump a little lower (same height as Knuckles jump). Yes Yes
4ANA-CRA0 Jump a little higher. Yes Yes
2ANA-CWA0 Jump a lot higher. Yes Yes
AANA-C4A0 Jump really high. Yes Yes
AANA-DYA0 Jump ridiculously high. Yes Yes
A2NT-CAG6 Only 6 chaos emeralds needed to become Super Sonic. Yes Yes
AYNT-CAG6 Only 5 chaos emeralds needed to become Super Sonic. Yes Yes
ATNT-CAG6 Only 4 chaos emeralds needed to become Super Sonic. Yes Yes
ANNT-CAG6 Only 3 chaos emeralds needed to become Super Sonic. Yes Yes
AJNT-CAG6 Only 2 chaos emeralds needed to become Super Sonic. Yes Yes
AENT-CAG6 Only 1 chaos emerald needed to become Super Sonic. Yes Yes
AANT-CAG6 Become Super Sonic without any chaos emeralds. Yes Yes
NTNT-CAHL 100 rings needed to become Super Sonic instead of 50. Yes Yes
FANT-CAHL 40 rings needed to become Super Sonic. Yes Yes
DENT-CAHL 25 rings needed to become Super Sonic. Yes Yes
BJNT-CAHL 10 rings needed to become Super Sonic. Yes Yes
AENT-CAHL 1 ring needed to become Super Sonic. Yes Yes
AANT-CAGY + AAPA-CAB8 Become Hyper Sonic without any emeralds. Yes Yes
Knuckles-specific codes
TB5T-CNCR Jumps as high as Sonic (slightly higher than usual). Yes Yes
PV5T-CRCR High jump. Yes Yes
AB5T-CWCR Super jump. Yes Yes
AB5T-C2CR Mega jump. Yes Yes
AB5T-DTCR Orbital jump. Yes Yes
A36A-CACW Only 6 chaos emeralds needed to become Super Knuckles. Yes Yes
AZ6A-CACW Only 5 chaos emeralds needed to become Super Knuckles. Yes Yes
AV6A-CACW Only 4 chaos emeralds needed to become Super Knuckles. Yes Yes
AP6A-CACW Only 3 chaos emeralds needed to become Super Knuckles. Yes Yes
AK6A-CACW Only 2 chaos emeralds needed to become Super Knuckles. Yes Yes
AF6A-CACW Only 1 chaos emerald needed to become Super Knuckles. Yes Yes
AB6A-CACW Become Super Knuckles without any chaos emeralds. Yes Yes
NV6A-CADA 100 rings needed to become Super Knuckles instead of 50. Yes Yes
FB6A-CADA 40 rings needed to become Super Knuckles. Yes Yes
DF6A-CADA 25 rings needed to become Super Knuckles. Yes Yes
BK6A-CADA 10 rings needed to become Super Knuckles. Yes Yes
AF6A-CADA 1 ring needed to become Super Knuckles. Yes Yes
AB6A-CACL + AB6A-CAHR Become Hyper Knuckles without any emeralds. Yes Yes

Unofficial codes

Code Description Works in S&K Works in S3K
General codes
RFLA-A6W4 Enable Level Select (A+Start at Title Screen). Yes No
RFTT-A6XW Enable Debug Mode (A+Start at Title Screen). Yes Yes
AVFA-AR74 Can Access 'Sound Test' Menu From Title Screen. No Yes
AKEA-CA3W Tails never gets tired of flying No Yes
AA7T-AAM2 Better night time No Yes
BCTT-LA3Y + BA8T-NA24 Knuckles can fight Knuckles. Yes Yes
ABZT-AA5Y + PKZT-B950 Tails follows Knuckles. No Yes
REBA-C6V6 Invincible against dynamic objects (bullets, enemies, for example), except Knuckles. Yes Yes
RZBA-E6YA Invincible against static objects (spikes, for example). Yes Yes
ABTA-NA7Y Invincible against Knuckles. Yes Yes
PJAA-CA8C Destroy enemy upon touching it (except Knuckles). Yes Yes
ABTT-NA3G Damage Knuckles upon touching him. Yes Yes
AAPT-CAB8 Don't use up rings to maintain the transformation of any Super/Hyper character. Yes Yes
CLRA-BA0Y Get One Emerald To Get Them All. Yes Yes
9WSA-BCET Only One Blue Sphere Needed To Win Emerald. Yes Yes
CXLA-EA7Y Bonus stage is always slot machine. Yes Yes
RHLA-E6ZY + BMLA-EA78 Bonus stage is always magnetic orbs. Yes Yes
RHLA-E6ZY + RHLA-E6Z8 Bonus stage is always gumball machine. No Yes
REPA-C6YR + REPA-C6YT + REPA-C6YW + REPA-C6YY
+ RFJT-C61Y + RFJT-C610 + RFJT-C612 + RFJT-C614
+ RF6T-C6V0 + RF6T-C6V2 + RF6T-C6V4 + RF6T-C6V6
+ RHPA-C6V0 + RHPA-C6V2 + RHPA-C6V4 + RHPA-C6V6
+ RHPT-C6VE + RHPT-C6VG + RHPT-C6VJ + RHPT-C6VL
+ RFPT-T6YC
Disable Super Transformation Music Yes Yes
NTBT-CB50 Never Die (except by drowning) Yes Yes
Sonic-specific codes
JAGA-CA98 Speed shoes don't run out with time. Yes Yes
AANT-CAHL Become Super/Hyper Sonic with 0 rings. Yes Yes
AANT-CAG6 Become Super Sonic without collecting Emeralds first. Yes Yes
AANT-CAGY + AAPA-CAB8 Become Hyper Sonic without collecting Emeralds first. Yes Yes
Tails-specific codes
JA6T-CA5E Speed shoes don't run out with time. No Yes
ABJT-CACJ Become Super Tails with 0 rings. No Yes
ABJT-CACA Become Super Tails without collecting emeralds first. No Yes
Knuckles-specific codes
HKXA-CA7T Speed shoes don't run out with time. Yes Yes
AB6A-CADA Become Super/Hyper Knuckles with 0 rings. Yes Yes
AB6A-CACW Become Super Knuckles without collecting Emeralds first. Yes Yes
AB6A-CACL + AB6A-CAHR Become Hyper Knuckles without collecting Emeralds first. Yes Yes
AB6A-DAJC Knuckles can float, push any jump button. Yes Yes
AP2A-DAR2 Knuckles Spin dash goes nowhere. Yes Yes
APYA-DAGC Knuckles has a shorter glide. Yes Yes
AP2A-DAEE Knuckles flies upwards. Yes Yes
1APT-CBHO Press down for a chaos emerald Yes Yes

Action Replay

Unofficial codes

Code Description Works in Gens
009760:6048 Red Spheres have no effect in special stages Yes
0097AE:6672 + 0097C8:4E75 Collision disabled for bumpers in special stage Yes
FFFE12:0063 Always have 99 lives Yes
FFFE21:0063 Always have 99 rings Yes
FFFE25:0000 Infinite time No
FFB038:00xx Have character ID of (00=Sonic, 01=Tails, 02=Knuckles) (controls things like wall-breaking and character-specific boss fights). No
FFFF0B:00xx Character modifier (00=Sonic & Tails, 01=Sonic, 02=Tails, 03=Knuckles, 04=Blue Knuckles). No
FFFFE0:0101 Level select and slow motion enabled. Yes
00380A:???? + FFF65F:0004 Sonic Color modifier(found by tailsisdumb make sure to replace the ???? with any 4-digit number) Yes
00381E:0006 Tails is affected by above code(found by tailsisdumb make sure above code is enabled) Yes
FFFFDA:0001 Debug mode always enabled (without holding A during level load) No
FFE439:0001 Only one blue sphere required to get the emerald (turn off as soon as special stage HUD appears or else special stage results screen won't register emerald) No
FFFFB0:0007 Have 7 Chaos Emeralds. No
FFFFB0:0707 Have 7 Chaos and Super Emeralds. Yes
FFFFB2:0?0? + FFFFB4:0?0? + FFFFB6:0?0? + FFFFB8:0?0? Emeralds in SRAM modifier. Replace ? with 0 = No Emeralds, 1 = All Chaos Emeralds, 2 = Hidden Palace Emeralds, 3 = Hyper Emeralds. Verified to work in Sonic 3 & Knuckles only.
006B68:0A94 Play as red Sonic (choosing to play as Knuckles produces Sonic with Knuckles' palette)

~courtesy of ShanMan

Yes
FFB15D:FFFF Blue Knuckles in first save slot. Save slot should be empty. The Blue Knuckles has Sonic's pallete, Knuckles' abilities(floating, etc.), Sonic's Sprite in Special Stage, Labeled as Sonic in Lives. The code is pretty unstable, crashes sometimes.
  • Alluseri was here
Yes
FFFE10:XXYY Stage/Act Modifier. X=Level; Y=Act. Set Y to 00 for Act 1, and to 01 for Act 2.
ID Name Works in S&K Works in S3K
00 Angel Island No Yes
01 Hydrocity No Yes
02 Marble Garden No Yes
03 Carnival Night No Yes
04 Flying Battery Yes Yes
05 Icecap No Yes
06 Launch Base No Yes
07 Mushroom Hill Yes Yes
08 Sandopolis Yes Yes
09 Lava Reef Yes Yes
0A Sky Sanctuary (Act 1 = Sonic / Act 2 = Knuckles) Yes Yes
0B Death Egg Yes Yes
0C Doomsday Yes Yes
0D Sonic/Tails End Sequence (must be set to Act 2) Yes Yes
13 Gumball Machine - Sonic 3 Bonus Stage No Yes
14 Glowing Spheres - S&K Bonus Stage Yes Yes
15 Slot Machine - S&K Bonus Stage Yes Yes
16 Act 1 = Lava Reef Act 2 boss / Act 2 = Hidden Palace Yes Yes
17 Act 1 = 2nd Death Egg Act 2 Boss / Act 2 = Master Emerald Shrine Yes Yes
Garbled in 1P, normal in 2P
0E Azure Lake No Yes
0F Balloon Park No Yes
10 Desert Palace No Yes
11 Chrome Gadget No Yes
12 Endless Mine No Yes
Yes

References


Sonic & Knuckles
Sonic & Knuckles title.png

Main page (S3&K|KiS2|Blue Sphere)
Maps (S3&K)
Achievements
Comparisons


Manuals
Print advertisements
TV advertisements
Magazine articles
Merchandise


Development
Hidden content (S3&K)
Bugs (S3&K)
Hacking guide