No missable achievements (plus 62 unknown)
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Defeat the Cycloid
Doodle something on the whiteboard in SP
Drink a beer in SP
Kill 50 aliens
Take steroids in SP
Knock out the talent at the talk show
Kill 100 aliens
Kill 3 aliens at once
Defeat the Battlelord in Las Vegas
Kill 250 aliens
Blow up 5 enemy gunships or dropships
Shoot down 20 alien fighters
Defeat the Alien Queen
Kill 10 aliens with environmental explosives
Kill 30 aliens with headshots
Find and steal a piece of poo
Kill 15 aliens with the monster truck
Get knocked down 10 times
Use a Holoduke in SP
Defeat the Battlelord on the Hoover Dam
Get hit by 10 Pregnator bombs
Defeat the Octaking
Defeat the Energy Leech
Complete the SP campaign on Easy Difficulty
Eat 10 pieces of food during the SP campaign
Kill 6 aliens with the forklift
Win a game of Alien Abortion in the strip club
Put a Trip Mine on a live alien
Foot stomp 12 aliens
Drink beer while on steroids or vice-versa in SP
Execute 20 aliens
Shoot down the blimp above the stadium
Complete the SP campaign on Normal Difficulty
Kill 15 aliens with melee attacks while on steroids
Kill 10 aliens with tossed objects
Watch the credits all the way through
Look at every page of a calendar in SP
Kill 10 aliens with Trip Mines
Kill 15 frozen aliens
Win air hockey with a score of 7-0 in the strip club
Drink all of the beers in the strip club
Carry the gold pistol through the whole SP campaign
Complete the SP campaign on Hard Difficulty
Unlock the secret closet at the end of the Forkstop
Earn a 1,000,000 pinball score in SP
Discover all ego cap rewards
Find all 3 helmets in the SP campaign
Kill all of the catfish in the underwater level
Listen to all phone messages
Complete the SP campaign on Insane Difficulty