Trophies, high scores
Another idea: As you go through the levels, you can have a special "event" (randomized, with a level requirement for instance), for instance a damsel in distress. She would be represented as are the monsters, and any hit dealt to her would kill her. If you clean the level without killing her, you "unlock" her, and she gives you a permanent boost at the start of each dungeon
Trophies, high scores Another idea: As you go through the levels, you can have a special "event" (randomized, with a level requirement for instance), for instance a damsel in distress. She would be represented as are the monsters, and any hit dealt to her would kill her. If you clean the level without killing her, you "unlock" her, and she gives you a permanent boost at the start of each dungeon