A few new features are being prepared for the PSP. Your main means of fire has been set to auto on the PSP, meaning you won't have to keep on pressing the fire button in order to strike your opponents. The system's 16x9 display will be used to display the action like a vertical arcade shooter, as along as you're willing to rotate your PSP 90 degrees in order to play, of course.
But the best new feature of the PSP version is its price: 4800 yen! That's almost 2,000 yen over the PS2 and GameCube versions, and with good reason! The PSP version includes a national ranking mode. Clear the game, and you'll get a password which can be input at the official Star Soldier site (via your computer, not your PSP) in order to get yourself placed. Who needs WiFi when you've got passwords and a computer!