Full list of all 12 Sonic The Hedgehog 3 achievements worth 200 gamerscore. It takes around 2-3 hours to unlock all of the achievements on Xbox 360.
You collected all seven Chaos Emeralds.
You scored 80,000 points.
You finished the game.
You completed the Icecap Zone.
You scored 40,000 points.
You collected a Chaos Emerald.
You finished the Marble Garden Zone.
You finished the Hydrocity Zone.
You scored 20,000 points.
You ran across water.
You got a blue gumball.
You collected 50 rings.