Discover a hidden room.
Kill 20 or more enemies on any level.
Defeat 25 enemies with the silencer pistol.
Finish a level without killing any enemies.
Answer 20 trivia questions correctly.
Answer 10 trivia questions correctly.
Beat the game, save the world.
Complete a level without setting off any alarms.
Finish any level in less than 20 seconds.
Defeat 25 enemies with Reagan's katana.
Answer 3 trivia questions correctly.
Complete a level.
Defeat 25 enemies with the shotgun.
Defeat 25 enemies with the assault rifle.
Defeat 25 enemies with the hand gun.
Destroy all of the fuel in the fuel depot.
Defeat 25 enemies with Gorbachev's blowgun.
Defeat 25 enemies with the bazooka.
Defeat 25 enemies with the grenade launcher.
Defeat 25 enemies with the Uzi.
Defeat 25 enemies with the minigun.