Gnawer

Gnawer is a dungeon crawler game where you play in a computer generated map each level getting a little more challenging.

The idea is to beat the level's boss to proceed as farther as you can and gain a high score. 

Each level gets more difficult, you get new bosses, some new enemy types and more items to use.

You have an AI helper that spawns with you and fights with you, it also collects items to use in its fight, tries to dodge bullets and support you. If it dies, you can farm enemies and if one of them drops the magic hat, you get it to respawn.