I'm not a puzzle player but I thought the levels were generally very good, nice difficulty curve. However, the last level I solved by doing random things until it worked. Felt slightly different to the other levels, I didn't feel lead to the answer.
The movement and mechanics seem very well designed, I like all the unique items and the magnet felt very emphasised. However, the jump felt kinda floaty? The peak of the jump he feels weightless, although this may be an animation thing not the actual mechanic.
You should definitely be able to aim while moving, its jarring to be locked while aiming, as you cant make minor adjustments and I often ended up having to be forced to restart even though I knew it wouldn't work. I also think you should be able to cancel the throw. Not sure if this is a function already but super frustrating to not be able to cancel a throw I know isn't going to work.
Everything looks amazing and very clean. Possibly the hub world should be changed? It feels a lil clunky to get into worlds by throwing magnet, maybe just auto open doors or require no aiming for level selection.
Overall, felt very fun to play and the concept is super interesting, could definitely go places with more timing related puzzles. Keep up the good work :D