the game is amazing, nonograms so far are hard but totally fair and solvable without having to guess a 50/50 which is amazing puzzle design,I'm on 100+ solved already and hoping to 100% it soon.
I have some QOL suggestions that hopefully could get implemented even as a opt-in or something, mainly greying out numbers you already filled in before completing the whole row, having to constantly stare and see which ones you have filled or not is hard on the eyes.
Another one is having a undo/redo button, sometimes you're deep on a solve and mess up accidentally and is hard to go back without having to restart the puzzle.
A nice to have also is the auto filling of 'x' when you solved a row/column already, not a big deal though.