Full list of all 44 Looking Up I See Only A Ceiling achievements. It takes around 0-1 hour to unlock all of the achievements in the base game on Windows.
The base game contains 15 achievements, and there is 1 DLC pack containing 29 achievements.
Reach Checkpoint VI.
Reach Checkpoint VII.
Reach Checkpoint VIII.
Reach Checkpoint IX.
Reach Checkpoint X.
Reach Checkpoint XI.
Reach Checkpoint XII.
Reach Checkpoint XIII.
Reach Checkpoint XIV-A.
Reach Checkpoint XIV-B.
Reach Checkpoint XIV-C.
Unlock all Endings.
Die for a spike trap.
Suffocate in water.
Die from stress and anxiety.
Die from an inexplicable weight.
Die because you couldn't make it.
Die because you can't do this anymore.
Die because you don't want to continue anymore.
Die because you failed.
Die and lose your only spark of hope.
Find Her studying in the Study Room.
Flip the light switch more than 10 times.
Press the code's buttons randomly for a lot of times, without composing the correct sequence.
Find them laughing at you.
Unlock the university door without cleaning the classrooms' labels.
Access the DLC "The Relapse".