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