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