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