Here is the full list of all 42 Pleh! achievements.
The base game contains 41 achievements, and there is 1 DLC pack containing 1 achievements.
I respect your wishes.
Push the chair 1500 times
Consider this your final warning
I AM EVERYWHERE
I wish we could stay like this forever
Thank you VERY much for playing!
This door was not one of them
Cracked the mainframe
Demotivation
Find all 10 hidden transcripts
Depression
If you're reading this, BIOSener.config installed correctly. If you're not reading this, BIOSener.config did not install correctly
Push the chair 500 times
10.17
Afterlife
Misery
Thank you for watching the credits!
I should have known.
I bet you think you're so funny.
Carry on.
Anxiety
Please don't take me away...
A clock, a piano, and a girl. What do they all mean?
Sing happy birthday twice
Remember to wash your hands!
Agony
Desperation
Push the chair 100 times
Please leave me alone
Dullness
Stop taking them away from me!
Push the chair 50 times
Push the chair 10 times
Suicide
Disappointment
Please come back...
Type "null" when null
Quit the game at the warning screen
Walk backwards for 10 seconds
Beat Pleh!
Press H to begin
Complete the new content update