This is an unexpected bonus! The Humble Introversion Bundle had just hit half a million dollars in sales, and to celebrate this milestone the Wolfire folks have included Dungeons of Dredmor as an additional game to the already-burgeoning pack. Early adopters can acquire the game now from their download page, while everyone else will receive Dungeons of Dredmor (plus Aquaria and Crayon Physics Deluxe) if they pay more than the average price advertised at the site.

If you're waiting for the source codes, then you're in luck as well: the source codes for Darwinia, Uplink, Multiwinia, and Defcon are now accessible to all Bundle customers starting today. As usual, all games in the Introversion Bundle (not inclusive of the prototypes) are available for Windows, Mac and Linux platforms.

The Humble Introversion Bundle page can be found here.