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