This is sick! I got stuck on level 4 a couple times from tech problems hitting the restart, and I might be too dumb to understand it to get past it also, but overall actually made me think and I love puzzles :) so this was so good, be proud of yourself. (let me know if there's a secret to getting past level 4 and I'll try again)
I initially thought if the key disappeared I would know that I got it, I went back for it more times than I think I needed to, but then I saw the little key icon on the bottom of the screen and I thought, "that's so smart!".
Also with the witchy music I thought this was a pumpkin :)