You beat Chemical Plant Zone 1 in under 45 seconds.
You got one Chaos Emerald.
You beat Emerald Hill Zone 1 in under 35 seconds in single-player or co-op mode.
You cleared the Emerald Hill Zone 1.
You played all four multiplayer zones.
You won 10 versus zones on Xbox Live.
You beat the game.
You got to the Casino Night Zone.
You became Super Sonic.
You stayed in Super Sonic mode for one minute.
You got all the Chaos Emeralds.
You beat the game in under an hour.