Prior to its release on Xbox Live Arcade, Spelunky was a freeware game on PC.
Derek Yu, Spelunky's creator, made the game using the GameMaker tool, and now using the HTML5 compatible GameMaker Studio, developer Darius Kazemi has ported the original game for web browsers.
The port, which took Kazemi about three hours, is not perfect, most notably for its lack of sound due to an incompatibility with HTML5.
Kazemi said that he is still working on improving the port, though the game is already fully playable at this point.
Spelunky can be played in any web browser here.
> Read Digital Spy's review of Spelunky
Watch the Xbox Live Arcade trailer for Spelunky below: