Robotstein is a mod for registered Wolfenstein, made by Brian Gunter. It was released on March 29, 2005.
The mod was listed as being a beta, and features only 3 new levels on Episode 1. However, the remaining 57 level slots are filled out, with the mod most likely being based on an old map set rather than the original Wolfenstein 3D levels.
Some new graphics appear, and as the title alludes to they are all robots. Weaponry was taken from Coming of the Storm, and source code changes include new episode names and increased health and ammo.
Never available on the Wolfenstein 3D Dome but instead posted on an external link, the mod was unavailable for many years.