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