Sonic the Hedgehog 2 (2013)/Hidden content

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Level select

Sonic2 iOS LevelSelect.png

The level select in this version is accessed in the same way as the 2013 version of Sonic 1. Start a "No Save" game with any character, and on the Sega screen, tap the letters S-E-G-A in order once the entire logo appears. A Ring sound will confirm correct entry. Then hold two fingers on the bottom of the screen and wait. Once the game reaches the title screen, it will immediately go to the level select screen. Alternatively, if using a controller, press Up Up Up Down Down Down Left Right Left Right on the title screen in "No Save" mode.

Hidden Palace Zone is listed beneath Death Egg Zone, but it can only be accessed after finding and beating it in a saved game or by exiting Proto Palace Zone (see below). Otherwise, it will be disabled and the game will play a buzzer sound when attempting to access it.

Swap "Tails" for "Miles"


Start a new game, and on the Sega screen, tap the letters A-G-E-S in order once the entire logo appears. Alternatively, if using a controller, press Up Down Down Down Down Up on the title screen. A Ring sound will confirm correct entry. This can be done on both a saved game and a "No Save" game.

Game configuration menu


A game configuration menu is accessible by playing sound 00 three times in the Sound Test. It has the following options:

  • Player: Choose any of the available characters/character teams. This also provides the option of playing as Knuckles with Tails following.
  • Items: Choose between Sonic 2 items, hidden Sonic 2 items (monitor contents are randomised like in 2-player mode), Sonic 3 items (adds the elemental Shields) and hidden Sonic 3 items. Enabling Sonic 3 items will also allow Sonic to perform the Insta-Shield.
  • Flight: Toggle Tails' ability to fly. Turned on by default.
  • Air Cap: Toggle the air speed cap from the original game. Turned off by default.

Debug mode

Sonic2 iOS DebugMode.png

Play sounds 01, 09, 09, 02, 01, 01, 02, 04 (the US/European release date of the original game) in the Sound Test, then select any level.

During gameplay, tap the HUD at the top left corner of the screen to activate Debug mode. While in Debug mode, tap - or + at the top of the screen to cycle through items, and press the Jump button to place an item. Tapping the lives counter while in Debug mode will return the player to the level select.

Playing a No Save game with Debug Mode will allow the player to enter a 2P VS game without connecting with another player online. While on the Stage Select screen, press Y on a physical controller, or L or 3 on a keyboard and a random character will join the game. The second player will always hang out at the starting point of a level, though, and will never move. This seems to no longer work by the Sega Forever update.

All Chaos Emeralds


Play sounds 04, 01, 02, 06 in the Sound Test. A Chaos Emerald sound effect will confirm correct entry. This immediately gives the player all seven Chaos Emeralds, enabling Super Sonic or Super Knuckles.

14 Continues


Play sounds 01, 01, 02, 04 in the Sound Test. A Continue sound effect will confirm correct entry.

8th Special Stage


An eighth Special Stage is available in the sound test on the level select menu. By playing sounds 00 through 07 the Special Stage entered when choosing the special stage will change. 00 is the first Special Stage and every number after that is the next highest Special Stage, with 07 leading to the new eighth Special Stage. This Stage features a purple floor (a color previously used exclusively in multiplayer Special Stages), a corkscrew loop, and a light blue Chaos Emerald.

Proto Palace Zone


As of Version 3.0.9 the original Hidden Palace Zone is accessible via the level select, complete with unused track #10. To access it, debug mode must first be enabled (see above), then play sounds 03, 03, 03, 0B, 10, 10, 10, 04 in the Sound Test, then simply choose "Hidden Palace" in the menu.

As with the original Mega Drive incarnation, the Zone is incomplete and stops at a certain point, though there are a few differences - the water slide works and is fully implemented, among additional platforms to make it easier for the player to advance throughout the Zone. The large emerald object acts as a warp that sends the player back to the level select instead of breaking to let the player enter the tube it's blocking.

Dying in Proto Palace Zone will not send the player back to the level select, nor will it restart Proto Palace Zone. Instead, the game will load the actual Hidden Palace Zone. Clearing the Zone by placing a Signpost or Capsule will send the player to Oil Ocean Zone.

Unused content

Unused monitors and various objects.[1]


Art Description
Unknown objects for Chemical Plant Zone. These can be placed with debug mode.
Spr cpzboss.gif
The animation for Water Eggman getting splatted with chemicals exists within Chemical Plant Zone's sprite sheets, but remains unused even in this version.
A pillar found amongst the Aquatic Ruin Zone sprite sheets.
A standing frame for the Balkiry. This can, again, be seen through debug mode.
Walking animation for Tocky. Like in the original game, this cannot be seen without debug mode.
Sonic2 2013 Sprite Hyper.png
Unused "HYPER" text for the Special Stage results, which suggests that Hyper Sonic and Hyper Knuckles might have been considered for this version.
Sonic2 2013 Sprite GoToHiddenPalace.png
Unused "GO TO HIDDEN PALACE" text for the Special Stage results, which suggests that the player could have entered Hidden Palace Zone through collecting all the Chaos Emeralds as it was originally planned during development of the original game.[2]


Art Description
Continue screen animation for Tails from the 2013 port of Sonic 1.
These are leftover Tails life icons from the 2011 Sonic CD and Sonic 1 port.
CDTimer Leftover.png
Leftover timer marks from Sonic CD (2011).
SonicCD11 Placeholder.png
Likely related to Retro SDK's level editor which is used to create the game. The same icon was found in the Sonic CD and Sonic 1 port.


Most of the objects listed here can be placed with debug mode unless otherwise stated.

Art Description
Tv super.png
"S" monitor which causes the player to become Super. Using this monitor is the only way for Tails to become Super Tails in this game.
Three Shields monitor which switches the items option from the config menu. Changes take effect either when the Act is restarted or when the next Act is reached.
Emerald Monitor. Breaking it will give the player all the Chaos Emeralds, or take them all away.
Spring monitor, which also exists in the Nick Arcade and Simon Wai prototypes. While the monitors above can be placed with debug mode, this one can't.
The Snail Badnik from the Nick Arcade and Simon Wai prototypes can be placed in Emerald Hill Zone with debug mode. It has the same movement pattern as it does in the prototypes.
Bee sprite.png
An alternate version of the Buzzer Badnik, placeable in Emerald Hill Zone. It behaves as it was planned out in concept art. Its shots burn bridges, which will harm the player unless they have a Fire Shield.
Sonic2 2013 Sprite MotherBubbler.png
The three-eyed fish Badnik has been made fully functional and can be placed in Chemical Plant Zone. It moves around slowly, but speeds up if it comes in close proximity with the player, dropping Bubblers as its attack.
Dropped by the Mother Bubbler Badnik and explodes after touching the ground. It can also be dropped individually with debug mode.
A stationary fireball for Chemical Plant Zone that harms the player, unless they are wearing a Fire Shield.
A ball for Chemical Plant Zone that will float in the air, and give chase if the player is in close proximity. When above the player's head, it'll explode and drop chemicals. The Bubble Shield can protect against this attack.
Aquatic ruin door.png
An Aquatic Ruin Zone door which closes as soon as the player passes through it. Unused in the original game and unused here, too.
A Grounder, but green. This was added in as a homage to the character from Adventures of Sonic the Hedgehog.
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.
A checkered ball in Oil Ocean Zone that is launched from a spring when a button is pressed. However, it behaves like the rolling checkered ball in the Sonic 1 2013 game rather than how it did in the original Sonic 2 and its prototypes.
Wing Fortress Zone platform that shoots a laser when it spins.
Wing Fortress Zone spinning object. It behaves the same as in the original game and hurts the player.

Egg Gauntlet Zone


Egg Gauntlet Zone data remains in the final game but can only be accessed through hacking. It was the first attempt at a Boss Attack level that had some original artwork such as mechanical palm trees and flashing lights, as well as artwork recycled from Sonic Crackers. It was to be a full Zone that acted as a testing facility for some of the boss machines rather than just have a level with bosses back to back. The Zone was nearly completed and needed just a few graphical changes to replace missing, unpolished, and placeholder graphics. Sonic Team did not approve of changing the location, colors, or graphical style so the level was scrapped and the Boss Attack level that was used in the final game was created.[3] A map of the level can be seen here, and a YouTube video of the Zone can be found here.

As of Version 3.0.9 the Zone was completely removed from the game. It was later brought back in the code when Sega Forever started maintaining the game.


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

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