This is more for all the newish people thinking about getting in the Retro gaming on the R-pi.
I have used pi-play and was a bit of a fan when it first came out. It is very simple to set up and get going. Thats all and good but at this point there are literally hundreds of ways to play retro games on a handheld. Retro pi is much more complicated to setup if you want to get fancy but a simple install gets you every thing pi play can do with the one exception being there sweet browser-based ROM uploader system.
I would say this might be a good project for someone who doesn't care how the front end looks and just want a simple project. But, the piPlay forum is been completely taken over by spam and has been for a while. This does not make the project look promising.
If you want to take a look here it is.
piplay-portableIn my humble opinion here are some better projects to look at.
Retro pie More systems, constantly updated, and better Front end.
Retro pie mod by Flood Same as above but with attract mode, a much better front-end. Not for portables.
Pi girl for a fun portable.
and there is always PSP hacking.
If the pi play guys kept there forum clean and up to date, maybe this would be a good option for someone who just wants a simple quick DYI project to play a few classic favorites on the go. But they don't so I wouldn't.