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.
Beat 100 aliens with leg kicks.
Unlock all upgraded weapons.
Complete the petrol station map.
Kill 15 boss aliens.
Complete the tropical hotel map.
Unlock all perks.
Complete the wasteland map.
Blow up 500 aliens with grenades.
Kill 1 000 aliens.
Kill an alien boss with the pistol.
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.
Empty all the rounds of a revolver with only deadly shots in less than 5 seconds.
Use every weapon during one game.
Kill 100 aliens.
Blow up 8 aliens with one grenade.