Loved the new demo! I think the game currently has a solid foundation to expand upon.
I think one piece of criticism I could bring up regarding the 2.0 demo is about that one fizzler that kills the magnet. I don't think its current design is all that great for its intended purpose.
Firstly, the symbol at the top looks like a smiley face, which is very confusing. I would recommend swapping that for something like the No Waiting road sign.
Secondly, the effect on the fizzler looks too much like the magnetic beams, which adds to the confusion. I'm not sure what solution could be used here, but perhaps it would help to use particles that look like the No Waiting sign.
And lastly, does it even need to be a fizzler that kills the magnet? In that one level where the fizzler appears, its purpose is preventing the player from bringing the magnet to the left. Well, you previously introduced those platforms that the player can stand on, but the magnet passes right through. Why won't you simply introduce a platform that does the opposite, i.e. the magnet can stand on it and be blocked by it, but the player passes right through? That would probably have more puzzle-oriented applications than a fizzler.