Description from the publisher:

R'lyeh is a terrible and ancient city, risen from the depths of the Pacific by a great curse. There, Cthulhu lies both dead and dreaming, waiting to consume any who venture near.

In Lost in R'lyeh, players are trapped in H.P. Lovecraft's short story, "The Call of Cthulhu". From the mysterious discovery of a profane idol, to dreams of a dark cult, to landfall in a cyclopean metropolis and Cthulhu's horrific emergence, no player can truly win...although the last player to escape will be the ultimate loser for that player will be forever lost in R'lyeh!

In terms of the gameplay, each turn choose to play either event cards and horror cards. Play the largest card sets you can to unlock ever-mightier powers. When the time is right, transition from playing cards from your hand to eliminating your array of escape cards. What's more, decide each turn whether picking up the whole stack will help you win, even though you're ultimately trying to get rid of cards.