Here is the full list of all 49 Alien Rage - Unlimited achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Find all weapons
Complete single player campaign on all difficulty levels
Find all audio recordings
Complete single player campaign on Hard difficulty
500 Kills With Explosions
Kill an enemy with every weapon
Use every weapon’s secondary fire mode
Use all weapons
Complete single player campaign on Brutal difficulty
Play entire campaign using only the pistol
Play entire campaign using only 1 weapon
Completely recover from damage 3 times during a multiplayer match
1000 Promethium Containers Destroyed
250 Kills With Melee
Reach a player score of 50,000,000
Get the most kills AND never die during a single multiplayer match
Play as an alien in a multiplayer game
Get the most kills during a single multiplayer match
Win 10 multiplayer games
Complete single player campaign on any difficulty level
Complete single player campaign on Normal difficulty
Defeat all Bosses
Defeat Vorus God Mech
Play as a human in a multiplayer game
Never die during a single multiplayer match
Join a multiplayer game
Defeat DF9 Sentry Mech
Unlock all player perks
Destroy the security control room
1500 Total Kills
Defeat Vorus Primus
Set the docking tower centrifuge to overdrive
500 Total Headshots
Defeat GX-7 Destroyer Prototype
80 Kills While Piloting Mech
Reach a player score of 25,000,000
25 Kills Using Mech To Step On Enemies
Defeat AA-19 Combat Mech
Defeat Mk XII Heavy Mech
Defeat Vorus Gladiator
Survive the Heavy room
Defeat Security Turrets
Take out the bunker
Unlock first Perk
Defeat Vorus Centurion
Lower the bridge
Find a new weapon
Find an alien weapon
Use any weapon’s secondary fire mode