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
Do Jumping Jacks 10 times
Do squats 10 times
End 10 streamings
Upgrade Dance to max level
Reach streamer rank 1
Upgrade Jumping Jacks to max level
Upgrade Draw to max level
Upgrade Squats to max level
Upgrade ASMR to max level
Get 1000 subs
Buy 6 zones
Reach 5000 viewers
Get 500 subs
Buy 3 zones
Buy 10 bikinis
Buy 5 bikinis
Do ASMR 1 time
Pop 10 extra viewers bubbles
Dance 1 time
Do squats 1 time
Do Jumping Jacks 1 time
Get 100 subs
Reach 1000 viewers
Reach 500 viewers
Get 20 subs
Draw 1 time
Buy 1 bikini
End 1 streaming
Buy 1 zone
Reach 100 viewers
Pop 1 extra viewers bubble