From the back of the book:
Welcome to the Secret War! With these Achtung! 2d20 Basic Rules, you’ll get your first glimpse into the hidden globe-spanning conflict between the forces of good and evil! Only you and your scrappy band of heroes can defeat the malignant forces of the occult, and the malevolent might of their Mythos masters!
Punch brain-sucking horrors in the tentacles! Ride drilling machines at top speed through terror-filled tunnels! Peer deeply into musty tomes of eldritch knowledge never meant for the eyes of mere mortals! Wield powerful magic and potent psychic powers to fight uncanny threats!
Achtung! Cthulhu 2d20 immerses you in a world of fast-paced pulp adventure, occult horror and incredible feats of derring-do. Explore ancient ruins and forbidden knowledge! Battle fanatical cultists, crazed scientists, evil sorcerers, deadly Deep Ones and bizarre alien threats!
Laugh in the face of reality-warping nightmares from beyond the stars! Grow in power, gain experience and develop new skills in a series of exciting globe-trotting adventures... until you’re ready to face down the mind-shattering Master of R’lyeh - dread Cthulhu himself!