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