Here is the full list of all 32 Deadlings: Rotten Edition achievements.
Complete all bonus levels.
Complete all bonus levels with maximum rank.
Complete bonus level 10.
Complete all levels in Nightmare Mode with maximum rank.
Complete 60 levels in Nightmare Mode.
Complete 45 levels in Nightmare Mode.
Kill the zombie with the other zombie.
Complete level 14 in less than 10 seconds.
Complete level 04 using one zombie.
Complete 20 levels in Nightmare Mode.
Collect 200 stars.
Complete phase 4.
Complete all levels in Normal Mode with maximum rank.
Discover a crazy mutators.
Kill over 100 zombies.
Complete phase 3.
Collect 150 stars.
Discover a freezing freezers.
Collect 800 brains.
Discover an awesome portals!
Complete 5 levels in Nightmare Mode.
Finish 20 levels without killing a single zombie.
Complete phase 2.
Collect 100 stars.
Collect 400 brains.
Discover a deadly lasers.
Unlock the Lazybrain.
Complete phase 1.
Collect 50 stars.
Collect 150 brains.
Unlock the Gasfat.
Unlock the Creep.