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