Strictly speaking the game is a port of Global Defence Force Portable rather than the original game. Portable (which certainly seems an appropriate title) was a Japan-only PSP version which included additional weapons for the two classes and seven new levels, all of which are present and correct in IfPS. It also features a multiplayer mode and a new English dub (the EU release of Global Defence Force had no speech). It is rated T for animated blood, mild language, and violence.