Post Apocalyptic. Gamma World, Fallout CRPG (series), Mad Max movies.
Our world is gone. The recognizable world around you is shattered and destroyed. It exists now as a backdrop for the adventures of gritty, battered heroes in piecemeal armor, some armed with flintlocks, some with swords and some with laser pistols.
Villains range from disfigured demigogues leading a horde of mutant followers to deranged cleaning robots armed with disintigrators.
It is our flawed and broken world, but with a different fantasy feel to it. There is no magic, but that which you find inside you. Courage, Hope and Determination.
Plus, what other genre could let you have a siberian tiger moreau armed with twin grenade launchers, backed up by a mutated squirrel with two heads piloting a gunship?
And the pair hunting down a deranged chihuahua moreau and his legion of mutant rebels.