It certainly has potential! The controls feel pretty good, level design is alright - I especially like level 5, it definitely had that "a-ha!" moment for me. The last level felt a little too confusing for my liking, the solution didn't feel like it was the intended one, maybe because the magnet door was just barely enough to stop the falling block. The option to change the colour of magnets was much appreciated!
All in all, I feel like with a story of some kind to keep the player engaged this should prove to be an enjoyable experience. Thanks for sharing the demo!