Acclaim Forsaken Open Source!!!
http://home.comcast.net/~wlm00/files.htm
Source code is here (it's abandonware now).
Minimum Forsaken requirements are:
P166 / P133 with 3D acc.
16MB RAM
Recommended requirements are:
Pentium 233
32MB RAM
And PSP has:
333 MHz
32MB RAM
So PSP can play Forsaken at playable speeds. Please, somebody try to port it... I want this game on PSP really badly!
EDIT: For people that don't know, Forsaken is Descent clone. It was made by Acclaim in 1998. Game is abandonware now.
Multi Player gameplay video:
http://youtube.com/watch?v=e6u81paVpps
Single Player gameplay video:
http://youtube.com/watch?v=FOKk6YuQgYc