I don't quite understand the intended solution for room 6, but I was able to cheese it a bit by doing a precise throw while the "-" block was attached to the "+" magnet. By doing this I was able to get the magnet in the path of the block without it touching the button— stopping the block from touching the button on the way down. Finding it hard to explain so I
attached a screenshot of my solution.
Viewing post in Untitled Magnet Game comments
I'll also echo some other sentiments about the restart button and it being overall unsatisfying to essentially get soft locked and have to restart the level. I also think it would be fun to have to exit each level where you entered! It was a bit jarring picking up the first key just to have the screen fade to black.
Overall, good stuff!