Cool.

Unfortunately long press didn't work for me with a trackpad (Safari on macOS), so wasn't able to flag at all. Maybe add a test for ctrl-click or shift-click?

Long press is for mobile browsers; use right-click on desktop.

I'm on a laptop with a trackpad — there is no right click. Usually Ctrl-click works as a right-click, but in this case it doesn't.

Two-finger click works for me (macOS).

oh, yeah, that works. And double three-finger click to clear. Still, ctrl-click should also work.

Control click would also be a good addition. Otherwise I keep losing!

Took me back to playing minesweeper as a kid. I managed to find myself in an end state that could only be resolved with a 50/50 guess. I don't remember if the classic version had this problem, but I think it would be nice to have a guarantee of no ambiguous boards.

Love it! 36 seconds for a beginners one :)