Here is the full list of all 19 Action Alien achievements.
Kill 10 000 aliens.
Earn a total of 10 000 credits.
Unlock all golden weapons.
Unlock all upgraded weapons.
Blow up 500 aliens with grenades.
Kill 15 boss aliens.
Unlock all perks.
Complete the petrol station map.
Complete the tropical hotel map.
Kill 1 000 aliens.
Complete the wasteland map.
Kill an alien boss with the pistol.
Beat 100 aliens with leg kicks.
Use every weapon during one game.
Demolish a part of a building with the grenade launcher.
Kill an alien with the last bullet of a machine gun or an assault rifle.
Kill 100 aliens.
Blow up 8 aliens with one grenade.
Empty all the rounds of a revolver with only deadly shots in less than 5 seconds.