Sonic the Hedgehog 2 (8-bit)/Bugs

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General bugs

Increased speed from a rolling jump

Sonic2 SMS Bug RollingJump1.png
Sonic2 SMS Bug RollingJump2.png

If the player jumps while rolling on the ground, they will rapidly gain extra momentum while in the air, more than they normally would if they jumped while running. This even happens if the player rolls off a ledge and holds forward while doing so.

Similar behaviour exists in the Nintendo 3DS version of Sonic Generations.[1]

Not fixed in any version.


Sonic2 SMS Bug StuckInLoop.png
Getting stuck on a loop.
Sonic2 SMS Bug BackwardsLoop.png
Running backwards through a loop.

Loops in this game have some strange oddities due to the way they are programmed compared to the 16-bit games. If the player runs into them at lower speeds, then there is a chance they can get stuck in the top-right corner. The player is unable to jump off and is thus forced to wait for a Time Over.

Additionally, when running towards a loop, if the player quickly presses Left on the exact frame they start running up the loop, Sonic will run backwards through it and appear to clip through the walls of the loop. The timing for this is very precise, but this is purely a cosmetic bug as the player will still make it through.

Partially fixed in the Game Gear version. The player apparently can't get stuck on a loop, but they can still trigger the animation error.

Invincibility music error

If the player reaches the Bonus Panel while Invincibility is active, and the Invincibility runs out after the Signpost lands, the regular level music will override the clear jingle and play over the results tally.

Not fixed in any version.

Level-specific bugs

Sky High Zone

Stand in the bottomless pit

Sonic2 SMS Bug SHZ BottomlessPit.png

In Sky High Zone Act 1, if the player stands on the collapsing bridge above the pit before the Bonus Panel, they will stop standing on the bottom of the pit and can safely walk along it until they jump and thus take damage from the hidden spikes in the pit. This behaviour is only in the Master System version of the game.

Fixed in the Game Gear version.

Go under the wall

Sonic2 SMS Bug SHZ GoUnderWall1.png
Walk under this wall here.
Sonic2 SMS Bug SHZ GoUnderWall2.png
Jump around this spot...
Sonic2 SMS Bug SHZ GoUnderWall3.png
...and things get weird.

In Sky High Zone Act 1, it is possible to walk under the wall in the same pit mentioned under the above bug and can move around underneath the terrain, however it is lined with spikes which will soon result in death. If the player jumps at a specific point (shown in the screenshots), they will end up being stuck out of bounds, complete with the camera shifting upwards and graphical glitches occuring. Waiting for a Time Over is not possible in this scenario, as the game will softlock as a result of Sonic being off-screen, thus requiring the player to reset the game.

Fixed in the Game Gear version.

Respawning 1UPs

Sonic2 GG Bug Respawning1UP1.png
Roll into this 1UP...
Sonic2 GG Bug Respawning1UP2.png
Then bounce on this spring...
Sonic2 GG Bug Respawning1UP3.png
Stop and backtrack here...
Sonic2 GG Bug Respawning1UP4.png
...and another 1UP appears!

In Sky High Zone Act 2, there is a 1UP Monitor located at the bottom near the beginning, which the player can find by dropping down the cliff at the start. If the player rolls off the ledge to the right of the monitor, bounces off it, bounces off the Spring to the left of the Monitor, then stop and backtrack after passing the Spring to the right, another 1UP Monitor will spawn. The player can repeat this process multiple times to essentially amass an infinite number of lives.

This bug only exists in the Game Gear version of the game. The smaller screen of the Game Gear, combined with the added momentum, essentially tricks the game into not processing the action. Therefore, the extra life respawns, but the lives counter increases, even though it maxes out at nine on-screen. It cannot happen in the Master System version due to the larger screen size, meaning the player cannot leave the area off-screen fast enough to trick the game.

Introduced in the Game Gear version.
Not fixed in any further version.

Gimmick Mt. Zone

Get the minecart stuck

Sonic2 SMS Bug GMZ MinecartStuck.png

In Act 1, it is possible for the player to get the final minecart stuck on the ramp that it flies off from. Immediately after jumping in, the player must jump out and run after it, then roll to catch up to it. If they get into the minecart on the exact frame that it rolls off the rails, the minecart will become stuck and the player will hear the minecart crash sound. There isn't much the player can do when the minecart is stuck like this, but jumping out of it will cause it to disappear instantly.

Fixed in the Game Gear version.

Crystal Egg Zone

Harmless electrical fields

Sonic2 SMS Bug CEZ HarmlessLightning.png

When fighting the final boss, attacking Eggman when he is charging up the electrical field will cancel the electrical field. If the player attacks him on the exact frame that he starts charging the attack, the electrical field's animation will not be cancelled and the arena will be constantly surging with electricity; however this will not harm the player. This effect lasts until Eggman uses the attack again.

Not fixed in any version.


Sonic the Hedgehog 2 (8-bit)
S2 sms title.png

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