Thank you for the quick reply!
I did try to play on my low-end laptop and also noticed the issue with the pointer not covering the full screen. The current version should have this fixed, but I discovered another bug (the cursor moves on its own). I will keep this feature in the game but put it on "off" by default, as on my main PC it runs fine and I don't get the bug.
I am happy to know you have completed a level on hard difficulty, congrats :)
I'll release just 1 more version right now, one with the confined pointer feature disabled as default