Thanks for the response. Luckily I managed to work it out.
For some reason none of the Retroarch emulators downloaded (not sure why).
My pi came with Noobs pre installed so not sure if there was a conflict somewhere.
I flashed it just with Retropie in the end and everything works as intended.
One issue I did have was my ps3 controller didn't work in game (it worked fine it emulationstation). It turned out that my wireless keyboard was being picked up as the control method in game and not the controller. Once I unplugged the receiver then the ps3 pad worked.
So all in all everything is now working fine.
I've got to say, this is an awesome piece of kit! :)
Cheers.