This is a PSP adoptation of Rise Of The Triad, 1st person shooter, originally developed by 3drealms/Apogee.

Changes:

– Slim psp support.
– fixed a memory leak bug, crashing the game after 5-10 minutes of playing.
– fixed intro screens / cut scenes
– some performance optimizations to rendering and timidity routines.
– added a PSP screen-size selector.On “Screen Size” selector menu, pressing [Right Arrow]
while at max screen size value, toggles between “Original” (320×240), “4×3” and
“Full Screen” modes.
– added Brightness control.On “Screen Size” selector menu, pressing [Left Arrow] while
at min screen size value, toggles between different brightness settings.
– new psp game icon.

http://deniska.dcemu.co.uk/rise-of-the-triad-psp-v-1-0-116921.html