Coded Arms is an FPS which was released on the Sony PlayStation Portable in 2005. It was developed and published by Konami.
You take the role of a hacker, trying to break the code of a virtual reality military training simulator which keeps running after it has been abandoned. It features random level design, with three different multiplayer modes (Deathmatch, Keep the Mark and Last Man Standing). One interesting element is that all weapons and equipment are identified by file extension names, such as .arm for guns, .cbx for grenades and .med for a health pickup.
It’s regarded by many as the best FPS on the PSP console. A sequel, Coded Arms: Contagion was also released for the PSP. A planned PlayStation 3 sequel was shown at the 2006 E3 as Coded Arms: Assault, but was later cancelled.