Achtung! Cthulhu: The Secret War

Game description from the publisher:

Europe is ablaze with the final conflicts of World War Two. As the Allies are caught unaware by a German assault in the misty Ardennes forests, the Black Sun unleashes mythos evil from ancient sites, hoping to overwhelm the Allies forces, whilst the Nachtwolfe attempt to power up a vast war machine that will bring about a thousand-year Reich. All the while the dreams of Cthulhu inspire cultists to rise up in preparation for his return!

As the heroes of Section M and Majestic in Achtung! Cthulhu: The Secret War, you must race across Europe on vital missions facing ancient terrors, recovering strange artifacts, and learning unspeakable knowledge to help defeat the forces of the Third Reich and the Cultists of the Old Gods. To aid the heroes' desperate endeavors, the players must learn to command the powerful but over-extended Allied forces to help halt the tide of evil!