Operation: Heimzahlung is the third mod released by Wolf Skevos-Jones (WSJ). It was released on March 22, 2003 only roughly four months after his previous project, the extensive Project: Eisenritter.
It features 22 levels played in a heavily modified EXE based on registered Wolfenstein. Many of the graphics rely on the aesthetic and design from the Spear Mission Packs (Lost Episodes) all heavily modified with a unique pallette.
The first levels take place outside, in an extensive, dark forest environment. Dungeons and castles dominate the remaining design.
Numerous new sounds and features can be found within the mod, including shooting an alarm, silenced weapons and numerous new guards including chain gun guards and a tailgunner.
Some sounds and music were lifted from Return to Castle Wolfenstein.
Though heavily influential on the modding community, it is still only available in DOS.