This week brings the much anticipated Portal: Still Alive to the XBox Live Arcade, downloadable for 1200 MS Points ($15). Originally hyped as a sequel to the original Portal, this new game is actually just the original game itself, expanded by 14 new levels and a developer commentary. I’d been looking forward to Still Alive but might have to pass on this one. There are more than enough games keeping me busy right now (Dead Space, Saints Row 2, Fable II, and soon Fallout 3) that I’ll think twice before dropping fifteen bucks on a downloadable expansion pack. Maybe Microsoft is charging by the megabyte, as this game clocks in at a mammoth 629 MB, the largest XBLA game to date. If you are interested in the download, though, (and you really should be, if you have never played the original Portal), you can grab it right now from the XBox Marketplace.