Here is the full list of all 23 Exit Limbo: Opening achievements.
Perform a 30 hits combo.
Perform a 70 hits combo.
Perform a 100 hits combo
Perform a fatality on a flesh zombie.
Perform a fatality on a sheep.
Perform a fatality on a rat.
Perform a fatality on brix/dix.
Unlock all special moves.
Start the game.
Finish the game.
Kill an enemy using a saw.
Die under a press.
Discover cross road.
Defeat Igor the Boar.
Kill an enemy with a press.
Survive the red Junkie.
Find a way to use a trash bin to solve a puzzle.
Jump on a barrel and perform a barrel run.
Do a full stomp combo + any special move.
Do a full kick combo + any special move.
Meet Bullocks.
Find the secret area in link road.
Decapitate a sheep.