Just got this bad boy yesterday and I'm like a kid at Christmas! ๐ The delight I felt firing up my old love, Desert Strike... Goosebumps! Seriously impressed with this bit of kit, and I'm enjoying exploring the options as much as the many many games! The effort put in by the community with GarlicOS and the ROM packs is simply magnificent.
Hundreds, if not thousands, across all kinds of retro consoles! Atari all the way through Gameboys, NES up to PS1. The default OS seems ok, but I only tried it briefly before switching over to GarlicOS which everyone seemed to be keen on. This guide was super helpful in getting me started.