I also read the user review, and it wasn't very good.
If you want a portable NES emulator you can just get a 3DS for $130 dollars and emulate NES, as well as other consoles. And if you want to take it even further get an NVIDIA potable tablet. They're pretty good from what I've heard.
Or a PSP
Also, I wouldn't be surprised if my printer could play NES games better than this garbage