Full list of all 12 Sonic The Hedgehog 2 achievements worth 200 gamerscore. It takes around 3-4 hours to unlock all of the achievements on Xbox 360.
Clear the Emerald Hill Zone 1.
Beat Emerald Hill Zone 1 in under 35 seconds in single-player or co-op mode.
Beat Chemical Plant Zone 1 in under 45 seconds.
Get to the Casino Night Zone.
Become Super Sonic.
Stay in Super Sonic mode for one minute.
Get one Chaos Emerald.
Get all the Chaos Emeralds.
Beat the game in under an hour.
Play all four multiplayer zones.
Win 10 versus zones on Xbox Live.
Beat the game.