Honestly I'm all for variety, innovation, and creativity, but theres a difference between HOW to beat a game (getting the next item to progress) and how DIFFICULT the game is.
The way the game plays out is fine, but the bosses and enemies should have had more health and dealt more damage. Also getting to a bosses or enemies vaunerability/weakness should have been more difficult. Because it's getting the crap kicked out of you and getting fired up and going back to try again that makes you feel like you've accomplished something.
Also getting the crap kicked out of you makes it "personal" to me, I develop a grudge against the boss, which makes it more exciting.
Maybe this game should have had difficulty settings?