A vast underground complex was discovered in Japan. Unexpectedly, an entire race of creatures, known as the T'lan, was found dwelling there, guided by a mysterious being called Nexus. The humans built a research facility near the underground complex, called Site Zero, and sent soldiers to protect the researchers and ensure that the fragile peace between humans and T'lan will last. As Derrick Cole awakens in a recovery facility near Site Zero, he fails to remember anything from his past. Apparently, he was injected T'langen, a fluid that was taken from the T'lan, which has unexpected effects on human organism. As the war between the humans and the T'lan begins, Derrick must first of all find a way to escape, with both sides being hostile to him, unaware of the role he will play in the future of both races.
Breakdown is a first-person action game. Though Derrick can use firearms, it is not entirely a FPS; much of the game's combat relies on melee moves and combos that Derrick learns, turning the game into a "first-person fighter". An unusual feature of the game is the completely physical interaction with the environment, which strives to be realistic. In order to force Derrick to pick up ammo, operate an object, eat food to restore health, etc., the player has to physically move the controller, imitating corresponding real-life movements.
The Japanese Xbox version of R:Racing Evolution comes with a Breakdown Premium DVD which features various concept art of character sketches, pre-release gameplay footage as well as E3 and teaser trailers.