Version Differences

This is a sub-page of Sonic the Hedgehog 2 (Sega Master System, Game Gear).

To do: Document more differences between the Master System and Game Gear versions, rip the alternate boss/Power Sneakers/good ending themes, attempt to include images, etc. Add more detail, elaboration, document Revision 2.2 of the Master System version, split the list up into appropriate sections, etc. Add a comparison of the strobing effects on the Nintendo 3DS Virtual Console version

The 8-bit versions of Sonic 2 are mostly identical, but besides the resolution there are some differences detailing the transition from Master System to Game Gear.

Master System to Game Gear#

General Differences#

Master System	Game Gear

• On both revisions for the Master System, the intro originally started with Tails already kidnapped. On the Game Gear version, it starts off with Tails running away as Robotnik's claw catches him. The sky in the intro also changed from a bright cyan to a very dark shade.
• In the Master System version of Aqua Lake Zone Act 2, the entire level is a murky green palette, and the waterline is invisible and at a fixed position near the top. On Game Gear, clean blue water visibly rises and floods the entire stage at the start.
• When Sonic drowns in the Master System version, he sinks with his mouth opening and closing, like the Master System version of the previous game. On Game Gear, he sinks with his mouth open, as in the console games.
• On Game Gear, "HIRO SSS" is credited in place of "SEMIMARU" and "TOSIYAN" is corrected to "TOSHIYAN" for the Program, and there is an extra credit for "RYU" under Thanks.
• When Sonic (and Tails) look upon the stars at the end of the credits, a sound effect is now played. This sound replaces the unused track ($92) from the Master System version.
• When Sonic enters the tube that leads to Scrambled Egg's boss arena in the Game Gear version, the boss music starts playing immediately, whereas in the Master System version it starts just as Sonic exits the tube.
• The end-of-Act tally counts down points slower in the Game Gear version.

Gameplay Differences#

• Several small changes are present to level geometry and ring layouts across the game. A notable example is a set of rings in Green Hills Zone spelling the word "END" (one of the level designers listed in the credits) was added. These changes are minor and don't appear to be done to make the stages easier to navigate with the restricted view as per the stage changes in the Game Gear version of Sonic 1.
• The geometry of several boss fight areas were made smaller to accommodate the smaller fixed screen. For example, the Green Hills arena is much narrower, and Crystal Egg's boss makes the horizontal pipe exit on the left invisible.
• Several boss fights are more difficult, partially as a result of the smaller screen size but also because the behavior of certain bosses was altered. Under Ground's boss now has the rocks bounce at unpredictable heights (which combined with the smaller screen space makes the boss much more difficult), Aqua Lake's boss continually moves towards Sonic, forcing him to jump and be bounced away before the orange sphere attack, and Green Hills' boss will now sometimes combine a high leap with a low roll attack rather than just doing one or the other. Crystal Egg's boss is not necessarily harder, but it does not follow exactly the same attack pattern as the Master System version, i.e. if one attacks it during the optimal openings on each play, it will result in the battle playing out exactly the same every time, but those openings and thus exactly the same scenario differs for each version.
• Power Sneakers exist as a one-off powerup in the Master System version, only appearing in Aqua Lake Zone Act 2. When this monitor is broken, a unique track is temporarily played, gives Sonic a trailing sparkle effect much like the invincibility sparkles in the console games, but it otherwise does not provide its usual speed-up effect. Likely because of this odd oversight, it is replaced by a Super Ring monitor in the Game Gear version, therefore making the Power Sneakers monitor unused in that version.

Audio Differences#

• The sound effect when Sonic spins on the wheels and orb in Gimmick Mountain and Crystal Egg is different.

Master System Revision 1.0 -> Revision 2.2#

Main Differences#

Revision 1.0	Revision 2.2

In Sky High Zone Act 1, there are several glitches to this falling bridge in Revision 1.0, due to the wall having no collision. While the Game Gear release fixes this via adding collision to the wall, the Master System Revision 2.2 fixes this by removing the bridge.

Revision 1.0	Revision 2.2

This rather difficult section in Sky High Zone Act 2 was made considerably easier in Revision 2.2 via making the tunnel wider, flatter, and easier to jump out of if you fall in and removing the first section of ceiling spikes.

3DS Virtual Console#

The version of the Game Gear ROM released for the 3DS eShop dims the strobing effect present in Crystal Egg Zone Act 3, likely to lessen the chance of inducing epilepsy.

Sonic Origins Plus#

The following content may induce seizures and has been hidden by default. Click to reveal:
Game Gear Origins Plus

The Game Gear ROM used in Sonic Origins Plus significantly slows down the strobing effect in Crystal Egg Zone Act 3, likely to further lessen the chance of inducing epilepsy.