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.
Reach a player score of 50,000,000
Unlock all player perks
Use every weapon’s secondary fire mode
Use all weapons
Kill an enemy with every weapon
Find all weapons
80 Kills While Piloting Mech
25 Kills Using Mech To Step On Enemies
Complete single player campaign on any difficulty level
Complete single player campaign on Normal difficulty
Defeat all Bosses
Defeat Vorus God Mech
Defeat DF9 Sentry Mech
500 Total Headshots
Destroy the security control room
Defeat Vorus Primus
250 Kills With Melee
Reach a player score of 25,000,000
Set the docking tower centrifuge to overdrive
Defeat GX-7 Destroyer Prototype
Defeat AA-19 Combat Mech
Defeat Mk XII Heavy Mech
1000 Promethium Containers Destroyed
Defeat Vorus Gladiator
1500 Total Kills
Find all audio recordings
Survive the Heavy room
Defeat Security Turrets
Take out the bunker
Defeat Vorus Centurion
Unlock first Perk
Lower the bridge
Find a new weapon
Find an alien weapon
Use any weapon’s secondary fire mode
Complete single player campaign on Brutal difficulty
Join a multiplayer game
Complete single player campaign on Hard difficulty
Complete single player campaign on all difficulty levels
Win 10 multiplayer games
Play entire campaign using only 1 weapon
500 Kills With Explosions
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
Play entire campaign using only the pistol