Chaos Master
You got all the Chaos Emeralds.
40 
Win
You beat the game.
35 
Fast Chemical
You beat Chemical Plant Zone 1 in under 45 seconds.
20 
Super Sonic
You became Super Sonic.
20 
Extended Super
You stayed in Super Sonic mode for one minute.
20 
Fast Emerald
You beat Emerald Hill Zone 1 in under 35 seconds in single-player or co-op mode.
15 
Xbox Live Racer
You won 10 versus zones on Xbox Live.
10 
Casino
You got to the Casino Night Zone.
10 
Chaos Emerald
You got one Chaos Emerald.
10 
Conquering Time
You beat the game in under an hour.
10 
Emerald Hill
You cleared the Emerald Hill Zone 1.
5 
All Multiplayer
You played all four multiplayer zones.
5