Here is the full list of all 18 OTXO achievements.
Unlock all drinks
Go fishing
Play fetch
Destroy the Heart
Collect everything from the gachapon machines
Collect all guns
Kill 15 enemies with doors without dying
Vault over 50 times
Kill 50 enemies with grenades
Kill 50 enemies with kunai
Order the ANIMAL drink at the bar
Kill an enemy with a thrown magazine
Roll over 100 times
Clear a room by only kicking
Die for the first time
Clear a room without using Focus
Clear a run on Impossible Mode
Clear a full run without taking any drinks