I just noticed that Hemisphere Games have an alpha demo up for their IGF 2009 Seumas McNally Grand Prize nominated ambient puzzler, Osmos. The 7mb installer is here. It's a game of cellular absorption, in which your self-propelled blob must absorb those smaller than itself to progress, while avoiding being absorbed itself. The trick is not to lose too much matter as your propel yourself. The resulting puzzle game is astonishingly soothing.
Trailer after the click.