Currently it uses some Othello/Reversi logic to swap cube colors, and that mode of play is pretty much complete except for an exit/win condition. Hopefully I'll get more time to work on this and add some new features.
I got a little reprieve from parenting duties this weekend, so here's the latest build of the PSP demo. I'm using Visual Studio to code and build for testing on Win32, then compiling against the PSPSDK and uploading to the real hardware. So far no major problems have come up, although it would be easier to have display lists working for using the standard bitmap font routines on the PSP.