Here is the full list of all 36 Hot Tub Simulator achievements.
End 50 streamings
Pop 100 extra viewers bubbles
Do ASMR 10 times
Dance 10 times
Draw 10 times
Reach streamer rank 1
Do Jumping Jacks 10 times
Upgrade Squats to max level
Upgrade Draw to max level
Upgrade Dance to max level
Do squats 10 times
Upgrade ASMR to max level
End 10 streamings
Upgrade Jumping Jacks to max level
Reach 5000 viewers
Get 1000 subs
Buy 6 zones
Get 500 subs
Pop 10 extra viewers bubbles
Buy 1 zone
Buy 3 zones
Buy 10 bikinis
Buy 5 bikinis
Buy 1 bikini
Do ASMR 1 time
Dance 1 time
Do Jumping Jacks 1 time
Get 100 subs
Reach 1000 viewers
Draw 1 time
Do squats 1 time
End 1 streaming
Get 20 subs
Reach 500 viewers
Pop 1 extra viewers bubble
Reach 100 viewers