Here is the full list of all 12 Alien Hominid HD achievements.
Complete game on Insane difficulty
Unlock all hats
Survive any challenge mode for 10 minutes
Complete game on Friendly difficulty
Defeat final boss without using a continue
10 consecutive head bites without touching the ground
Complete game on Normal difficulty
Eat 50 KGB Agents with Yeti
Attain 1000 kills during one game
Destroy 25 buildings in one game
Reach 5000Km in Super Soviet Missile Mastar
Complete first level