Here is the full list of all 40 Mayhem in Single Valley achievements.
Rescue all falling passengers.
Free the spider.
Find all 64 collectables.
Give Mom a flower.
Help an old lady.
Rescue your first clone.
Rescue 16 duct tape clones.
Rescue 32 duct tape clones.
Rescue 64 duct tape clones.
Help a swimmer in need.
Complete clone labs without killing a clone.
Cure a rhino.
Cure a gorilla.
Cure a lion.
Cure a bear.
Cure a monkey.
Bring Pops to Maud's grave.
Bring Bob back from the dead.
First upgrade.
Upgrade something to max.
Max upgrade Jack.
Save Single Valley.
Survive the zoo.
Go beyond the fence.
Cure Bob's pet rat.
Cure with explosives.
Find your first collectable.
Find 16 collectables.
Find 32 collectables.
Rescue all missing children.
Catch a fish.
Find the cave painting.
Complete the golf cart mini-game.
Escape The Void.
Break a wall with the wrecking ball.
Protect the mega batch.
Help Miss Jenkins out.
Use log cutter to cut down a tree.
Help Verity with her quest to find true love.
Swim in neighbor's pool.