Rage developer id Software's seminal first-person shooter Wolfenstein 3D is 20 years old.
To celebrate, id's John Carmack has recorded a director's commentary for the game, viewable below, where he discusses Castle Wolfenstein 3D's development while playing the original DOS version.
id Software has also launched a free-to-play browser-based version of Castle Wolfenstein 3D, available to play at wolfenstein.bethsoft.com.
"On the SNES version, you couldn't shoot dogs in a Nintendo game, or not back then. They all had to be changed to evil-eyed German rats," Carmack reminisced. "I had to go along with the fact that the blood had to be changed to green because you can't actually shoot people. So they had to be aliens wearing human uniforms, or something."
New Wolfenstein avatar items are also now available on the Xbox Live Marketplace, should you want to wear a themed t-shirt or don a Classic B.J. Blaskowicz Mask.