Well this is only the second game I've seen that takes advantage of magnets to fit the theme, and it definitely does it quite well. Ignoring a bit of finickyness with the cheese and good ol' physics.
The puzzles were definitely quite interesting to figure out how to solve and had, what seemed like, a decent amount of solutions. Intended or unintended. Though having all the physics based boxes definitely made a lot of the puzzles a lot more about specifically moving them, rather than the actual puzzle.
Specifically I'd say it was the worst in the one level where there is the jump box and normal box at the top and trying to get them down was almost impossible because they would just barely get stuck at an angle in the hole the were supposed to drop through.
Otherwise though the only other suggestion I have would be to make missing the "cheese shots" a little less punishing. Since it's such a limited resource and you can just barely miss it sometimes, especially since it looks to still be a child of the player while it is shot, which lead to a lot of turning around and uh... using my "electromagnetic powers" to turn it all the way around with me.
Definitely a fun one though.