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