Deniska has released Rise of The Triad version 0.9. Rise Of The Triad is an old FPS game by 3D Realms, and Deniska has ported the game on to the PSP. Here’s the message from him:

INSTALLATION

- select between the shareware and full versions (shareware game files are included; you can purchase the full version from www.3drealms.com)
1.5 users: copy contents of 1.5 folder to ms:/PSP/GAME
1.0 use EBOOT.PBP from 1.0 folder with data files from 1.5 folder (make sure your include .rott directory)
2.0 Please let me know if either version works with the latest eboot loader for 2.0 firmware [EDIT] I got reports that it works on 2.0 :-)

If you own the full version of the game use the EBOOTs from the "full" directory with the DARK WAR data files.

CONTROLS

Due to obvious PSP limitations, some game functions are not mapped in the default key configuration.
If you don't like the control layout/functions - you can re-assign them in the controls menu.

GAME PLAY

THIS IS STILL A BETA VERSION! So it may be a bit unstable.
Refer to original documentation for details on game play.
Network/multiplayer modes are not supported in this release, but you should be able to use some multiplayer levels in "exploration" mode
Note that full game's levels may take up to 1 minute to load.
During this time you'll see a black screen with some sounds, so be patient. (I may want to overclock the full version in the next release to make it load faster)

TODO

MUSIC SUPPORT
NETWORK/MULTIPLAYER SUPPORT - hmm, this may take a while
I'll release the source code once I patch major bugs.

Download: [Rise Of The Triad v0.9]

Thanks for the update and the email, Deniska!