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