I'm going to throw in a suggestion of my own here.
Meritous. It's an odd combination of Zelda style dungeon crawler and bullet hell shmup. You attack with a circular wave which not only hurts enemies but nullifies bullets too, which is essential since enemies from the beginning shoot tons of bullets at you. The wave is chargeable, but the longer you charge it for the longer you're without it. Your character can be upgraded to have a shield, stronger wave and shorter charging/cooldown time. It's a challenging game.