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