A label on hover would be nice — or even persistent labels to the right of the circles. I also wonder if instead of black, a dashed outline with a transparent center would make more sense, since you're cutting.

Regardless: This is lovely.

Fun! Some feedback:

I filled every square, but had errors. I received the "keep trying" alert. The alert was accurate, but it was annoying that as long as the puzzle was complete (every square filled) AND incorrect, I had to dismiss the alert every time to keep going. So if I just changed one square, and the puzzle continued to be filled but wrong, the alert showed up again. Perhaps using an inline error message rather than a modal would be less friction.

Also: when completed the puzzle correctly, I was told "Congratulations! You have completed the puzzle correctly in Om Os!" — which was much shorter than my actual time. :)

Good point, thank you - I'll have a think about how to make it less annoying.

Re: the timer, whoops! I'll fix that asap.

Glad you enjoyed it and thanks for taking the time to give me feedback :)