Here is the full list of all 13 LIMBO Demo achievements.
That's not right
Exploration off the ground
Prepare a dry landing
Involves heavy lifting
Beneath the arthropod
Don't pull the lever just because you can
Ride the crates
The crate is key
Vertical passageway
Don't let gravity keep you down
Perseverance has its own reward
Complete the game in one sitting with five or less deaths
Running off will get you nowhere