Portal: Flash edition
Thanks to tOdd for posting the link to this Flash version of Valve's Portal. People not running Windows might want to crank up their mouse speeds to the hyperactive setting commonly found on that platform because some levels will require it. I've only gotten halfway through Level 15, but I'll probably figure it out once I eat something. Of course, I can't endorse it until I get farther in as I haven't seen any lava yet, and everybody knows LAVA = STrAGETY.