The X-Arcade is natively supported by the OUYA game console and simply acts like a single game pad. This means it will work in the menus and in supported software. Unfortunately however, the OUYA developers made both players on a dual/Tankstick controller both act like the same controller, so you can't play 2-player games this way. One way to work around this limitation is to instead use 2 of our Xbox 360 adapters along with a USB hub instead.
The trackball also works on it as a mouse. For a Tankstick you will need to use a USB hub to connect both USB connections.
RetroArch
RetroArch allows you to play many emulators all from one app, including MAME games. Due to the limitiation mentioned at the top of this article, you will need to use 360 adapters to play 2-players however.
MAME4Droid
MAME4Droid on the Ouya store only works with one gamepad, meaning you can't play 2-player games at all currently (as of version .139). We recommend that you simply use Retroarch instead.