It's a survival horror game made by squaresoft.
It's set in our world, but with a few extra bits stuck in.
Living inside the cells of all organisms are micro-cells called mitochondria.
Some say(in this game) that it was a part of an organism that the first bacteria absorbed at the start of life on this planet.
Other debating scientists theorize that the mitochondria may have purposely merged into the cells of bodies as nucleic parasites.
Anyway, The year is 2000. and aya brea is going on another case.
2 years ago, the mitochondria awakened inside the cells due to an over populated body of a woman. Codenamed mitochondria eve. In the first game aya fights the horrid mutations and finally defeats eve. Now, the NMC's(Neo-mitochondrian creatures) are almost wiped out. Untill one day, at a skyscraper hotel.....
Here's an example of an NMC. An NMC rat, from the first game:
And a movie of gameplay:
http://au.youtube.com/watch?v=P7IEOP0nRHY&feature=related