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