The 9th World- The Lost Continent

Humans, or at least, different humans to what we know today.   A billion years of evolution has left humans unrecognizable to today's version. On top of that, there are mutant varieties and other intelligent races produced by biodesigners of the past, however, this is a harsh world to not be a "regular" human in, and other species and mutants often face animosity, if not outright hostility.