Complete all single player levels 1-5
Find all secret collectibles
Kill 50 aliens in a row without taking damage in single player
Kill a total of 25 aliens in single player
Complete "Hydroponics" in Co-op Assault
Complete any single player level without using any items
Complete single player levels 1-5 on Elite difficulty
Complete 'Interface' single player mission without using a health pack
Complete CO-OP Assault level 1, 2 or 3 without either player dying
Collect all the logs throughout the game
Fire every weapon and use every item in single player
Kill 20 aliens within 30 seconds in single player
14375
0
