Here is the full list of all 57 It came from space, and ate our brains achievements.
Kill 100000 aliens.
Make 25.000.000 amount of Coins in total.
Finish 6 multiplayer games on insane without dying.
Finish 3 multiplayer games on insane without dying.
Finish 1 multiplayer game on insane without dying.
Finish the first six levels on insane.
Finish the first six levels on hard.
Died 123 times.
Finish the first six levels on medium.
Revive 5 people using medkits.
Finish block ship on any difficulty.
Finish block launchpad on any difficulty.
Finish block scrapyard on any difficulty.
Finish block suburbs on any difficulty.
Shoot 95471 times.
Buy all shotgun upgrades.
Finish with the highest score in a multiplayer game 10 times.
Finish block industrial on any difficulty.
Finish block navy on any difficulty.
Finish block planet on any difficulty.
Finish the first six levels on easy.
Buy all rocketlauncher upgrades.
Kill 7 aliens at once.
Finish block crash site on any difficulty.
Kill 10000 aliens.
Finish block countryside on any difficulty.
Place 5 turrets.
Reach 75x multiplier.
Buy all machinegun upgrades.
Pick up 100 upgrades dropped by the S.W.A.T. Drone.
Finish block highway on any difficulty.
Buy all laser upgrades.
Finish block city on any difficulty.
Reach 50x multiplier.
Finish block hospital on any difficulty.
Buy all plasmagun upgrades.
Finish with the highest score in a multiplayer game.
Use the shield 5 times.
Kill 1338 crawlers.
Use the searchlights 5 times.
Place 15 mines.
Kill 1000 aliens.
Buy all pistol upgrades.
Kill an enemy close to a player with one health.
Reach 25x multiplier.
Staying alive while other players are waiting to respawn.
Die for the first time.
Complete all Campaign levels on Easy
Complete all Campaign levels on Medium
Complete all Campaign levels on Hard
Complete all Campaign levels on Insane
Complete Rooftops (Campaign) on any difficulty
Complete Clinic (Campaign) on any difficulty
Complete Alleys (Campaign) on any difficulty
Complete Sewers (Campaign) on any difficulty
Complete Riverside (Campaign) on any difficulty
Complete Cave (Campaign) on any difficulty