What would it make it interesting? I'd hook up a breakpoint to the check for 0 HP and just add HP.

It'd make a good debugging tutorial at least. The process of finding the right place to add HP isn't always simple (in other games) and you could always go through modifying game logic / items.

Heh. I think wizard mode pops up a dialog when you die "Are you sure you want to die?". Same effect, but probably less trouble!