I liked playing the demo. I like how the solutions to the puzzles are logical but not always obvious.
Maybe it's me, but I couldn't change the throwing arch, however I wanted to. Would this break the puzzles? Visually, the dots and arrow arch gave me the feeling I should be able to.
But besides that, I had fun playing the game, the overal atmoshpere is quite cute and the magnet mechanic is amazing and lends itself for a lot of cool puzzles.
Good luck on the rest of development!