I was able to change the mapping for the included controller in the game menu. When I was playing Astyanax the jump/attack buttons were reversed. The controller isn't responsive at all, and is even worse than the Retron 5 controller. I haven't tried another controller with it yet. The only other usb controller I have is an Xbox 360 Windows controller.
The menu seems cropped, but the games seem ok on mine. It would make sense to have the native ratio as the default.
I'm more disappointed in the sound quality. I have only played a few of the games, but every NES that I played had sound issues. Either there were sound effects missing like the ref in Ring King. He doesn't make any noise at all, he just flails his arms. There was music missing in that game too. 1943 also had music and sound effects missing, as well as in Gun.Smoke.
What is concerning to me is how the system was working without being plugged in. Is it possible that the hdmi cable is powering it? I haven't tried it yet with a composite cable.