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