Pressing two keys simultaneously is pretty hard, I had to push them a few times to get it right.
I don't really understand what "one wood" or "one lead" is, so at this point there's no guessing. It would be nice to, for example, guess the density of a material, not the weight of one piece(?) of it.
Except for that, I really liked the art and sounds, they were really light-hearted and pleasant.