A perfectly transferred classic. The only thing I can say is that it would be possible to add full-fledged keyboard controls, not just numbers. I also noticed that you have a backlight for numbers if you select one of them in the field, but why not make a backlight for comments on numbers when selecting one of them? In short, look at mobile sudokus, they have a lot of interesting little things like that.
GameplayAddictiveReplayability