Really fun! The character controller is much better and whilst the art may not be final - the magnet and robot have a good amount of expressiveness. The simple act of throwing the magnet to unlock a door for a level is small but makes the game feel more based around the magnet, similar to how in mario odyssey you need the hat to just dispense moons into the ship.
The puzzle elements were great, especially the gate that is moved by the magnet.
I didn't notice any major cons or issues, i think the game plays and looks well and so long as there are fresh mechanics for more puzzles (and sound design) it could go on the market in a moments notice.
The initial tutorial section is well made and I think the idea of needing to throw the magnet into a pipe to unlock a door out the level could be good for other levels, since you would also have to account for retrieving the magnet. However this could complicate things and would require some small tests to see if its positive or negative for the puzzles.
Great demo, thank you Mark!