DrPocketsnes should yield playable RPGs on the 770 and action games on the 800. It is a *lot* faster than snes9x, which gives about 5 fps on the 770 for games that use transparencies and pallete-changes and the raster effects.

... To answer your questions yeah on-screen buttons are the answer - see tak's excellent work on FCEU.

Onscreen taps generate normal X and SDL mouse events (leftclick). So you just detect for taps within a rectangular region. This is not difficult.

Here are the buttons i drew for uqm.

You can see em in action in this demo game.
http://pupnik.de/aliens-1.0.2_Nokia.tgz

I did make some progress porting DrPocketsnes v6. If anyone wants to take a stab at it, I'd be glad to help. I've uploaded my work-in-progress (Codenamed "The Horror") to my site here.

http://pupnik.de/DrPocketSnes_Nokia_The_Horror.tgz

The basic idea was to substitute the gp2x specific stuff with snes9x code. You can get the original DrPocketSnes9x code at Reesy's site.