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