A Global Game Jam entry from students at Carnegie Mellon, Balloon Man is a pleasant, dream-like little game in which a man holding three balloons rises upward (an "upscroller" rather than a sidescroller, if you will) past a somewhat surreal skyscape. Various obstacles float in space, and if a balloon intercepts one, it pops -- lose all three balloons, and you lose, of course.
Waft your mouse pointer across the man to "blow" him -- left, right, down, or up -- to avoid the obstacles. Gusts of wind are uncertain, of course, so positioning him precisely is difficult, which is part of the game.
It's not hugely challenging, but isn't intended to be; it's more of a little art game, evoking a dream-like sensibility, and completed within a few minutes. But quite enjoyable for what it is.