Batman is a mod for registered Wolfenstein, made by Ian Skevos-Jones. It was released on September 20, 2003.
WSJ assisted with the coding.
The mod features 24 seamless levels and a number of coding changes. New music is featured as well. Most graphics have been replaced, with the mod taking place in the DC Comics Batman universe, featuring many characters from there.
The storyline is well written and quite extensive.
Gameplay is particularly atmospheric and though mapping quality lacks a little at times, it all blends together quite well.
A sequel was released three months later.
It is still only available in DOS.