Huge news !
My friend Jbam released yesterday an HEAVILY improved version of RetroPie called "HAPPI game center". It's clearly much more than a tweaked RetroPie.
Please check it out : http://happi-game-center.com/
(choose English and click on the top right menu)
For Pi 2 only unfortunately. (binaries are optimized for it and the emulators used are heavier on resources)
--> he replaced MANY emulators with better versions, optimized some of them at source code level (PSX at 100% speed for instance), made some homemade pixel-shaders that give a CRT-like rendering which is really amazing (with no slowdown) - you all read about my complaints regarding MAME4all rendering
- , added many emulators / platforms (PGM, fullspeed Amiga 1200, PSP, ScummVM, SegaCD/32X...). ATM "MAME" is kinda broken but the FBA build supported many arcade systems (like PGM !!).
It's meant to be used with an USB controller.
(I'm cross posting this in the pifba & mame4all thread)
He spent a couple of fulltime months doing this (12 hours a day or so). He has to get back to work so doesn't know if he'll be able to continue as he has to make a living (he is an independant game developer). I think if there is a huge response and if we support his work, he'll be able to spend some more time on it ; amazing stuff is planned for the future, I'm not sure I can share the information here
Of course, source code will be released (it's on a repo right now I think) so improvements will eventually be backported to RetroPie.
BTW, please don't hesitate to tell me your remarks about the distro here. I don't want him to be flooded with questions, I'll filter them here (or on another dedicated thread).
Edit : he initially made this for a friend & himself. He needs to clean up the source code before making it available, please be patient