Here is the full list of all 38 Heavy Burger achievements.
Play 100 Custom Games
Start a 4-Player Game
Beat Any Hard Challenge Without Dying
Beat Any Hard Challenge Without Collecting Speed Bonuses
Beat Any Medium Challenge Without Shooting
Beat Any Medium Challenge Without Dodging
Complete the Seaside Slam Single-Player Challenge
Beat All Hard Challenges
Beat All Single Player Challenges
Complete the Easiest Single-Player Challenge
Complete the Drowning In Enemies Single-Player Challenge
Kill 3 Opponents With One Laser Shot
Complete the A Crime Well Done Single-Player Challenge
Complete the Carroty Champ Single-Player Challenge
Get 100 kills in any Hard Challenge
Complete the Surrounded with an 8-Ball Single-Player Challenge
Complete the Martial Law Single-Player Challenge
Complete the Barrel of Monkeys Single-Player Challenge
Beat All Medium Challenges
Bank $100 in any Hard Challenge
Complete the Pop 'N Lock Single-Player Challenge
Complete the Police State Single-Player Challenge
Complete the Kicked in the Cue Ball Single-Player Challenge
Complete the Chop 'N Wok Single-Player Challenge
Complete the Medium Rare Single-Player Challenge
Complete the Pocket Aces Single-Player Challenge
Complete the Chasecake Single-Player Challenge
Complete the Quadsimoto Single-Player Challenge
Complete the Double Trouble Single-Player Challenge
Beat All Easy Challenges
Complete the Pool Party Single-Player Challenge
Complete the All My Children Single-Player Challenge
Complete the Maze Craze Single-Player Challenge
Complete the Grandma's First Rodeo Single-Player Challenge
Clear the table in Side Pocket
Complete the Softer Than Jam Single-Player Challenge
Complete the Harder Than Jelly Single-Player Challenge
Complete the Tutorial Single-Player Challenge