High Constitution
To get High Constitution keep using a magic spell and keep using it even though
you are out of mana. don't be scared if your health goes down. If you use the
spell enough you hp will go back up and your constitution will be maxed out
Editor: Add Unlimited Levels
(Unverified) To get unlimited levels basically go to a set of stairs (going up or down) and input SHIFT + 9 (for stairs going up) or SHIFT + 0 (for stairs leading down). This replaces the level that was at those stairs with a new one and new objects.