All achievements in this title update are self explanatory but for this one simply just walk into 6 rooms. You can also walk into a room and back and forth a couple times to get this, 3 rooms, and starting room all done.
Per Trombonafide if you do the RItual achievement first (confirmed with the huntress code, not 100% on the rest) it will put you in a room and pop all but the dieing achievement in one go. Then can just die.