Here is the full list of all 57 Bunch of Heroes achievements.
Eliminate 35.000 zombies
Eliminate 1,000 Walking Coffins
Complete a multiplayer mission without damaging any allies
While playing with 3 allies get to survival's wave 9 without anyone dying
Complete all Mars missions
Complete all missions
Complete 10 4-player missions
While playing with 2 allies get to survival's wave 9 without anyone dying
Burn 1,000 Zombie Chickens
Eliminate 100 Flying-Saucers
Eliminate 200 Martians with melee attacks
Perform 100 Ultra Attacks
Reload your extra weapon 1,000 times
Roll 20 times while on fire
Get over a 1.000.000 points in survival
Eliminate 200 Zombies with market cars
Survive up to the 20th wave in Santa's map in any difficulty
Pickup 1,000 weapons
Eliminate 1,000 Zombie Evaders
While playing with 1 ally get to survival's wave 6 without anyone dying
Eliminate 1,000 Zombies with bayonets
Check out the Credits
While in survival mode get to wave 12 playing alone
Complete a mission without picking up any weapons
Place 100 turrets
Eliminate 200 zombies with melee attacks
Eliminate 1,000 Radioactive Zombies
Eliminate 200 Martian with shields
Kill the Martian King
Get to survival's wave 5 in less than 3 minutes
Kill 200 Strong Martian
Protect 50 cheerleaders
Perform a 80 kill combo while in survival mode
Eliminate 1,000 Zombie Chickens
Eliminate 500 zombie astronauts
Eliminate 723 zombie chickens, 821 basic zombies and 394 zombie astronauts
Defeat Fatzi
Complete all cemetery missions
Complete a mission with each of the characters
Complete 1 mission without picking up any Ultra Charges
Defeat Jazzy
Complete all farm missions
Defeat Fred
Defeat Pumpking
Pickup every weapon in the game
Complete a mission with full health
Complete a mission without dying
Eliminate 1,000 Basic Zombies
Kill a Martian Teleporter in survival mode
While in survival mode and playing alone: get to wave 3 without having been damaged
While in survival mode and playing alone: get to wave 3 in less than 5 minutes
Reach a combo of 60
Reach a combo of 40
Reach a combo of 20
Eliminate 100 Martian Teleporters
Eliminate 1,000 Generals
Kill 5.000 Martians