In 90s I really liked puzzle games and played a lot of them. Lately I very rarely see a puzzle game that I really want to play all the way to the end.
Hence, dont take this as a negative feedback, although I did stop after maybe 6 levels.
Puzzles were basically quite good actually. I would have loved this back then, but now it just felt yet another puzzle, and any small issue would make me end playing already.
First problem, which wouldnt be a problem if there be a story, was the levels recursive system, one depth is okay, but one it goes two, and I think this went three layers down, that feels like I have to start memorizing things, which is not what I want. I dont want to memorise things in puzzle games, but I want to solve puzzles.
Second was when the magnet levels came. It was otherwise actually pretty fun idea, but I absolutely hated that when I used magnets to shrink the level, I had to remember what was between there.
That was the point when I decided I had tried enough. Two different things to memorize was too much for me.
The controls were good, and things were essentially pretty easy to figure out, that only thing that took, perhaps too long, especially when considering that I did read the instruction texts, which actually did say this, but didnt remember it anymore.
But what I kept trying constantly was to move my character into this dead end piece, and then I would try to flip that dead end piece while my guy was inside it, this was since there have been countless other games where system was that. I just couldnt figure out how to get it to rotate while I was inside, so finally I resorted to hints, which showed that I was actually supposed to swap those two white pieces.
So yes, it took basically bit too long to figure that one out, which was mainly since it was contrary to how other bit siilar kind games have worked before, but then again, that hint system was a saver there, so that was excellent addition.
Basically comes to my mind that might be worth pointing it out to a player that you can swap those tiles, but, on the other hand, maybe it is better not to, but instead perhaps point out to hint system instead. For while it might have been good to having been told I can swap those pieces holding my hand, then I would have missed the hint system, and that hint system is actually pretty good if you are stuck because of a new mechanic you havent figured out, since then you always know just to click the hint button and find out that new mechanic, if that is the problem.
So maybe do add more hand holding, as in telling what to do, on that part, but not telling directly to swap those tiles, but to uose "H" for a hint. That could be perfect solution.
While I played this only very short time, and stopped playing early due to feeling bored due to memorizing things, this was more to do with me not being much interested in puzzle games anymore, rather than game being bad. I actually think your game was probably quite good, just cant say for sure since I tend to feel so negative about puzzle games lately.