From the website:
Cthulhu: A Deck Building Game is a cooperative deckbuilder for 1 to 6 players set within the Cthulhu mythos. Players work cooperatively as Investigators to banish the Elder Gods and their minions. Be wary. The Elder Gods will attempt to stop the Investigators through attacks-both psychological and physical. If all of the Investigators have their health or sanity reduced to zero the Elder Gods triumph! Cthulhu includes 12 different Elder Gods, 21 unique Investigators, and hundreds of minions, mythos horrors, and library cards to ensure no game is ever the same!