This is nice! I got stuck and gave up when there got to be nodes with 6s on them, but that's just because I'm in class. Given that the only reason to select an

This is nice! I got stuck and gave up when there got to be nodes with 6s on them, but that's just because I'm in class. Given that the only reason to select an edge right now is to delete it, perhaps the delete action could be mapped to a click, rather than a click plus a backspace. Also, a reset level button would be nice.