I wish there was a better way to switch between pencil marks and writing final answers. I put up with multiple clicks on my phone because I only have one finger, but I have a keyboard and a mouse with two buttons -- maybe holding spacebar would toggle, or right-clicking or something.

That's a fair critique. I wasn't sure to allow additional controls because that would involve overriding browser actions, which may bother others and be inconsistent, and also is unintuitive. Definitely a more involved HTML5 game would require it, but I anticipated a casual level of players who only a few would be long term repeats.

Looks good. Would be even better if it had a more fluid mobile experience :)

Thanks. I admit it makes a poor mobile experience because of the design focus for the mouse. In addition the layout practically revolves around the ad block (chosen because it looks the cleanest and purportedly has the highest click rate).

If the site gains momentum then I'll build a mobile version. Right now I think 11% visitors are mobile, and some tablet players do complete games.

tried to play it with my galaxy note, as the stylus registers mouse click events. there was about a half second delay between tap and action.