F.E.A.R. is first person shooter where you play a special forces soldier that specializes in hunting down paranormal evil. There is a lot of blood.
FEAR is a horror themed FPS from Monolith, makers of the equally pants-shitting Blood series. In the game, you play a nameless soldier for First Encounter Assault Recon (See what they did there? That's an acronym), tracking down a guy named Paxton Fettel. He is a psychic commander of a battalion of cloned soldiers. He also eats people to read their memories.