I just bought one this week, they can be rather difficult to navigaes with some menus seeming to swap the OK and back buttons on the controller. I chose the RetroPie Infinity 64gb Image (https://www.arcadepunks.com/to-infinity-and-beyond-the-new-64gb-pi-image-from-dz/) and expanded the storage with a 32gb USB stick using the included Eazy Hax Toolkit (https://www.youtube.com/watch?v=VO3LwOt9kpk) for extra PSX games - The background music stopped working when I added the USB so I had to transfer the music files onto the USB storage.
I've been having some fun on PlayStation "Micro Machines V3" and "I.Q.: Intelligent Qube" (AKA: Krishi IQ)
Can't wait to get stuck into some Amiga games from the old days such as "Blood Money" and "Silkworm".
- I'm still working to get Mame Arcade to recognise my DualShock 4 controller.