Thank you so much for such a detailled feedback, very instructive to read ! the cut off levels issue has been brought up some times, we think it happens when the game is not played fullscreen, which is our bad, thank you for playing :)
Ah, I see! Fullscreen does fix this. I thought the game didn't have fullscreen because the button didn't work, but it looks like that's an issue with itch's randomizer. When visiting it on the actual game page, it fullscreens just fine.