Astrostein is a mod for registered Wolfenstein, made by Spifferaneous. It was released on April 25, 1999.
Spifferaneous made his mod in 1998 and 1999, with deep inspiration, almost obsession (according to the Read Me) with Ryder's set. Three episodes were fully finished, though the remaining three can easily be played. Some of these levels are either full copies or based on original Wolfenstein maps.
Most graphics have been replaced, and the outer space atmosphere is definitely felt.
ECWolf Port Edit
This mod was ported to ECWolf in 2015 by AstroCreep, with extra features such as brightness levels, flat textures and updated sprites. Also includes Bruce Ryder’s demo as an extra episode. Two versions exist, one with sprites from WolfenDOOM and one with sprites from the Mac version of Astrostein. Was also updated again with updated enemies and weapons for Astrostein ASE Special Edition.