Lecky@Lecky,
The Revo K101+ plays the following:
1. Gameboy Advance (.GBA .GBK)
2. NES (.NES)
3. PC-Engine / TG16 (.PCE)
4. Sega Master System (.SMS)
5. Sega Game Gear (.GG)
6. Sega Genesis (.SG)
7. Gameboy Color (.GBC)
8. Gameboy (.GB)
FolioIt can play GBA games because it was designed as a clone; the hardware architecture is "close enough" to the original GBA that the games run natively, without emulation. The Genesis used a similar setup as the GBA in terms of hardware (GBA was an ARM7+Zilog Z80; the Genesis is a Motorola 68k+Zilog Z80), so I'd wager it's "easier" for the Revo to emulate that than the SNES. The SNES used some odd Ricoh processor, and was architected so that cartridges could "add on" extra processors/pipelines as needed, which makes the SNES moderately more complex to emulate, and the Revo probably just doesn't have the horsepower to accurately emulate it.