Full list of all 15 Thomas Was Alone achievements worth 1,000 gamerscore. It takes around 3-4 hours to unlock all of the achievements on Xbox One.
Finish the game.
Find both achievement pickups in 'Y+1, X+1'.
Find all achievement pickups in the game.
Find both achievement pickups in 'Generation'.
Find both achievement pickups in 'Design'.
Find both achievement pickups in 'Iterate'.
Find both achievement pickups in 'Invert'.
Find both achievement pickups in 'Purge'.
Jump 1600 times.
Find both achievement pickups in 'Associations'.
Bounce on Laura 100 times.
Die 100 times.
Find both achievement pickups in 'Origin'.
Find both achievement pickups in 'Array'.
Find both achievement pickups in 'Spawn'.