Loved the atmosphere and the color schemes. I agree with some of the other comments here about the floaty movement and the awkward key mapping. The grappling hook is the highlight of the game and feels really good. The kunai were pretty solid as well.
You've got a cool aesthetic and interesting ideas, so I'd focus on developing a good movement controller and more feedback from actions (sound effects especially) to really solidify your gameplay.
Kudos, too, for packaging what you had into a complete experience with titles, instructions, and an ending!