I beat it and thought it was okay. The only bits of feedback I have are: 1) let us use the up arrow key to perform an action the same way the W key does, and 2) don't make us time springboard jumps on moving platforms, because that just results in making the player wait for two differently-moving things to line up. I also noticed it wasn't consistent or clear where the signs' ability-changing zone was, but this never resulted in a cheap death; just a bit of confusion.
Music could do without the quacks, though.