I got a demo disc for the new God of War game for pre-ordering it at GameStop. I popped it into my slim PSP and had at it while waiting for my movie to start.
The graphics are pretty mind blowing for the PSP. They look just like the PS2 versions. In fact the whole game is just like the PS2 versions. The boss fights with the "hit the button" mini games are still there. The fixed camera angles are still there (and they still work well.) The only difference I noticed was the new magic system. I stole a spell from a Persian guy after i kicked his ass. The demo ended right after that, but I'm guessing you get your spells from bosses this time around.
So long story short, if you want God of War in your pocket, then this is exactly what you need. Doesn't look like anything very unique is going on here, but awesome non-the-less.
Sidenote: My hand started to hurt. I think the slim is too slim...