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