Halten Sie! is a mod for registered Wolfenstein, made by Laz Rojas. It was released on December 24, 2002.
Lifted from a WolfenDOOM scenario, the mod features 10 levels, played on Episode 1, and a number of changed graphics and sounds.
As with Rojas' only other Windows/PC mod, Escape from Totenhaus, the VGA is not functional on all computers, and using the original Wolfenstein files is recommended.
No source code changes are featured, and it is thus playable in SDL.