Very fun. I really liked your dungeon design. It looks like you put a lot of work into making it interesting. I can't really think of any flaws in this game. It's definitely reminiscent of early Zelda games.
36 out of 37, because the game is a bit lacking in story. That's simply my personal preference though. It sits well without much story, but had I not read the game's description I'd be a bit quizzical as to why I'm attacking these periscopéd duck creatures with a pitchfork.