Here is the full list of all 57 Zombie Hunter achievements.
Kill Splithead.
Reach 500 kills.
Complete all the missions of region 1.
Unlocked region 2.
Kill Zelvis.
Buy your first weapon.
Reach 100 headshots.
Kill Redspike.
Reach 50 kills with automatic.
Reach 50 kills with sniper.
Reach 100 kills.
Reach 50 headshots.
Kill Kyofu.
Upgrade 15 time your weapons.
Kill 4 zombies on strike.
Reach 25 headshots.
Reach 50 kills.
Kill Dr. Muscle.
Reach 25 kills.
Open a mistery box.
Kill a civilian "by error".
Lost a match.
Upgrade your weapon for the first time.
Reach 500 headshots.
Buy 10 different weapons.
Unlocked region 3.
Unlocked region 4.
Unlocked region 5.
Reach 50 kills with pistol.
Reach 50 kills with bow.
Reach 50 kills with bazooka.
Use 10 Spankys.
Use 10 dogs.
Use 10 radars.
Use 10 hollow bullets.
Kill all the super zombies.
Complete a perfect match.
Completa 25 perfect matchs.
Complete all the missions of region 2.
Complete all the missions of region 3.
Complete all the missions of region 4.
Complete all the missions of region 5.
Kill 10 zombies on strike.
Kill Bubbles.
Kill 1000 Prickles.
Kill Zordor The Clown.
Complete all the missions.
Kill Zrim Reaper.
Kill Sergeant Z.
Kill Captain Trout.
Kill LordNight
Kill The Twins.
Kill Headless Walker.
Kill Fat.
Kill Silent Freezer.
Kill DeathKiss.
Kill Maniatic