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