Fun game! I had a hard time with the wall-jumping for some reason, but with persistence I got it. (For some reason the second wall-jump always seems much harder to pull off than the first.)
I love the boss battle! I gave up on it after failing a dozen times, but I see how with practice I could eventually do it. It's kinda nice that when you die you just go back and try again; gives it a very forgiving, casual feel, while still being a challenge.
Beautiful work with the sprites, the sound FX, and the level design too. Amazingly polished for a weekend jam! My only suggestion might be to turn down the background music. It's pretty loud. :)
Keep up the great work!