MagiK from PSPDev has released Descent for the Playstation Portable.
Descent is a futuristic arcade style flight game. Originally developed by Parallax Software Descent features 3D gameplay in underground corridors and tight mineshafts.
Your specially designed vehicle is equipped with guns and missles and you are able to pick up and upgrade new weapons to add to your arsenal. While many played this game heavily on the PC there have been releases on the Playstation, Sega Saturn and Machintosh platforms as well.