"The Cthulhu Mythos, also known as the Lovecraft Mythos, is a shared universe created in the 1920s by American horror writer H. P. Lovecraft.
(User Summary)
Several video games have been created based on the premise of this universe. Generally of the survival-horror genre, the titles have however varied in their gameplay mechanic over the years."
Source: Wikipedia, "Cthulhu_Mythos", available under the CC-BY-SA License.