Wolfenstein 3D preceded the legendary game Doom in the pantheon of 3D shooters. You assume the role of OSA agent B.J. Blazkowicz, who must escape Castle Wolfenstein and defeat Nazi scientists and soldiers who have crafted monsters using paranormal techniques.

The game has been completely redone for the iPhone, including an all-new control system for the iPhone made by John Carmack, Id Software co-founder.

System requirements call for an iPhone or iPod touch running iPhone 2.0 software or later.

Wolfenstein 3D was, long ago, released under the Gnu General Public License (GPL) as open source code, to enable game developers and others to tinker with the game's underpinnings. Carmack has released the iPhone game's source code as well. The code is of little to use to non-iPhone app developers, but it's there for anyone who's interested.

In a posted to the Web site and attached to the source code dump-- from Id Software's Web site, Carmack explained the process behind bringing Wolfenstein 3D to the iPhone, including some failed attempts to bring other games like Orcs & Elves--a game Id Software created especially for mobile phones.