i saw this board a while back....
and just ignored it as its a really badly designed.....
you were better off buying a bog standard Common Ground PCB for about half the price....
because thats basically what it is that you have
(and dont buy the 6 button PCB this seller sells, buy the one from the Sudomod community, like Erik Gees)
the only saving grace is the joystick (and i have a feeling that might be upside down, but could be wrong on this)
the ribbon connector part is a good idea, and something i was going to implement....
but on this board its designed really poorly as its on the side of the PCB rather that in middle facing straight up....
the part you solder to the Raspberry Pi is also poorly designed, and justs adds extra height if using the connectors that come with the kit....
plus you have the half a mile long ribbon cable, just in case you actually need to wrap the Pi in something

.....
(but once you've got it all working, if you do get it working... you can always buy a shorter cable to make things look a little more cleaner)
if you have any trouble figuring out what GPIO are used for the controls, just ignore the ribbon connector part of the kit....
and just wire up the controls yourself to whichever GPIO you want to use
the audio circuit is also as basic as it gets, and its nice that the headphone socket is there...
but it means your limited to the design, or you'll have to start adding bits to make the audio better
but the kicker is that the board comes with no support, .....
its not worth the money IMHO.....
.