Kill 100 aliens.
Kill 1 000 aliens.
Kill 10 000 aliens.
Beat 100 aliens with leg kicks.
Blow up 500 aliens with grenades.
Use every weapon during one game.
Empty all the rounds of a revolver with only deadly shots in less than 5 seconds.
Kill an alien with the last bullet of a machine gun or an assault rifle.
Demolish a part of a building with the grenade launcher.
Kill an alien boss with the pistol.
Unlock all upgraded weapons.
Unlock all golden weapons.
Unlock all perks.
Complete the wasteland map.
Complete the tropical hotel map.
Complete the petrol station map.
Blow up 8 aliens with one grenade.
Kill 15 boss aliens.
Earn a total of 10 000 credits.