For the next 24 hours (started at 9am Pacific Time, actually), Acebloke expects to be hosting a beta version of his new game Zetris 2.
While obviously part of the Tetris genre, Zetris 2 bears some distinct variations from the norm in that, not only are you playing sideways without the ability to rotate your shapes, but you're also playing against yourself. The longer you drag it out, the better your score. Of course, by yourself isn't the only way to play, there are also various multiplayer options available, however, you won't get to try those unless you join the online game being hosted right now.
Acebloke warns us that there are still some bugs as this is a beta, but there should not be any game-breaking problems.