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