See the PiPlay Advance Board in Action
From Shea Silverman – the man behind the emulator frontend PiPlay comes a PCB that attaches to the Raspberry Pi Zero that gives you buttons and a screen so you can setup your own portable retro gaming device.
Still in development, the YouTube video (shown below) gives you a sample of what to expect from this PCB. It shows the device starting up and loading a game and playing. The board in the video has quite a small screen attached but it is definately viewable and will only serve to make any device made from this even smaller.
You can read more about this project on Shea Silvermans website at – http://blog.sheasilverman.com/
or alternatively, here is the PiPlay Advance PCB in action: