Extinction: The G.M.O. Chronicles is a weak-sauce entry in the infected/zombie horror genre. It's got a rambling plot full of a whole lot of "seen that before" with a few minor twists. It really should have been called "Extinction: Rise of The Parkour Mutants". It is a barely tolerable entry to it's genre.
So why mention it here? Despite the rambling, stumbling, not very engaging plot there is a tiny little bit of creativity that could be pilfered for zombie/infected/apocalypse RPG. The infected in this are mutants that develop throughout the film becoming less human, the film does depend on this for it's major action but doesn't go into it enough, but it does have some ideas worth pilfering.
The end of the humanity is caused by a retrovirus meant to be used to help big bad agri business quickly manipulate crops at a genetic level, of course things go wrong it gets out and allows lots of species to mutate and to cross breed. The result is zombie like mutants that develop into specific strains or "species" each with a range of limitations, behavior, and abilities that are a tiny bit more interesting then another dead guy trying to bite you. Some of the infected/zombie/mutants spit spores, projectile barbs, and sprays of icky goo some scream and some aren't really animals anymore so aren't prone to being hurt the same way animals are. Definitely worth using for a zombie/infected/mutant-apocalypse campaign. After a while plain old zombies get a bit dull and it becomes about the other survivors, mutant however can keep people on their toes. Watch out for the parkour mutants.