I don't often feature two-player games, with people whacking on the opposite site of the keyboard, because, well, the basic dynamic sucks. And anyway, we PC gamers are basically recluses. If we had friends, we'd be playing board or tabletop roleplaying games, and even when we play online, we generally prefer to solo instead of dealing with a bunch of whining guild mates. So I'm left testing a 2-player game playing left-hand-against-right, which really sucks, and anyway, I suspect the portion of our readers who'd play such a thing is small.
But Make My Head Grow is a hoot.