I wasn't sure about the stars either, but the difficulty has honestly grown on me :) I'm a massive fan of difficult games outside of jams, and the lack of workarounds for finding the stars feels very Getting Over It! It's refreshing to have no shortcuts for a jam game like this.
I don't blame you for struggling with the block behaviour, it's a big dilemma to have 😔 I think they turned out really nicely though, I forgot to mention in my original comment but the little physics interaction at the start of LV7 really hammered that home for me. For someone with little design experience you managed the physics extremely well!
I found exactly what you were talking about in LV6 too while I was trying to get down that bottom area early- trying to push the grey boxes across the gap to push the ones on the other side, etc etc, I did notice the physics being a bit inconsistent there. It didn't really matter in the end since I didn't need to be doing what I was doing, but I did see what you're mentioning!
Magnetic effect makes sense for the anti-gravity, I do see what you were going for :)) Jam time restrictions strike again 💔