Warhammer: Shadow of the Horned Rat [GOG PC]
until June 10th 10AM Pacific
The game is included as part of the Warhammer Skulls Digital Goodie Pack, which also includes wallpapers, concept art, a soundtrack, some PDFs, and 15% off Warhammer merch. After claiming you'll see one entry in your library for the game and one for the rest of the goodies.
https://gog.com/game/warhammer_skulls_digital_goodie_pack