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