The main menu is made up from a bunch of configuration files, nice alternative to EmulationStation and maybe even a little redundant.
The default entries only search for one extention, yet the emulator framework supports much more (eg: only zip for Nestopia by default). The content scanner from RetroArch is much smarter in that regard.
The menu is somewhat non-intuitive, for most people A and B are swapped and adding or removing favorites can eventually lead to deletion of copied games if you are not careful!
Date, time and timezone can not be changed from settings.
Battery, feels very last century at a whoping 1050mAh. I think the PCB takes up too much space, wouldn’t it be better to fill up that entire module with a LiPo instead? Even the space below the speaker is vacant, together they seem to fit a 3000mAh cellphone battery.
The way the keypad works, makes it unusable in RetroArch unless you enable unified controls. This was easy enough to do, yet remapping inputs is still impossible without editing the configuration files by hand.