I'm returning to the tradition of posting downloadable games on the first Friday of the month. This month we have Spelunky, a retro-inspired cave exploration and treasure-hunting game. The levels are randomly generated so the game is different each time you play, but I've found that they are always rather difficult. The art style is crisp and charming and the controls are tight, if a bit complex. It's definitely the type of game that could keep you busy for a very long time.