So I decided to get back into a game I played years ago,
Hyperiums. It's a free, browser-based strategy game in which you build up planets' economies, raise fleets and armies, and generally try to be the coolest dude in the universe. There are big alliances that evidently have grueling wars with each other over territory and whatnot. The first two or three days are kinda slow, since you're just waiting around for enough money to do anything, but I've found that it's quite entertaining to manage stuff after you're trying to take care of four or five planets.
If any of you interested, feel free to message me in-game. The name is Zvin. I also think it'd be cool to have an XKCD alliance, but who knows if enough will want to join it.

What they (mathematicians) define as interesting depends on their particular field of study; mathematical anaylsts find pain and extreme confusion interesting, whereas geometers are interested in beauty.