C64 emulator (Vice) 480x272 native
Gives a whole lease of live to the device. £30-£40 for a new opendingux handheld, not bad. :-)
Is C64 fullspeed with sound? If so might get one of these
I have only tried two games on it so far (Platoon and Rick dangerous) and yes they are Full speed. And that is even when I use "Resid" SID emulation which is more accurate
For demo's however, in particular those that use irq loading while showing a section, it slows down to a crawl. (this would be the stage where it would need to emulate two cpu's in C64 and the 1541 drive.)
For games it works very well.