Beat the second timed tunnel with 55 seconds or more left.
Get to the second tunnel without obtaining a single weapon upgrade.
Destroy the alien tower at the end of the water level.
Score 100,000 points in an Xbox Live Co-op game.
Beat the first timed tunnel with 33 seconds or more left.
Collect 4 different weapon power-ups.
Complete the game in Xbox Live Co-op mode.
Complete the game in Arcade mode using only 1 credit.
Complete the game in under 12 minutes.
Get to the first tunnel without losing a life.
Collect 3 different weapons in the second tunnel.
Complete the second tunnel with a score of 100,000 or more in Arcade mode.
