on top of linux or android?
Android is Linux, so either way it runs Linux. I imagine that it's running the UAE4ALL emulator. The review mentions: "With the card present, the Armiga boots up a standard-looking Linux kernel which originates from the Linaro project.", but the website mentions that if you boot without an SD card it will load Android from its internal memory.
The hardware, if anyone is interested:
http://cubieboard.org/2013/06/19/cubieboard2-is-here/IMO it adds very little value to the cb2 in this format. They could at least have added a proper 9-pin joystick interface to it. The one with the floppy drive is a bit more interesting.
