I answer a little late (but as I just arrived on the forum then ...).

Unfortunately, Moonlight is only compatible with Nvidia cards. Pa**ec is the only viable solution for Radeon / AMD cards ownners.

About Pa**ec, I tested it under retropie: performances are bad and system updates can sometimes be problematic.

The best is to realize a dual boot "Retropie / Raspbian lite" with the raspbian only dedicated to Pa**ec (automatic launching at start, drivers for joysticks, Wake on LAN to computer, etc ...).

If some people are interested, I will offer a step-by-step guide for Pa**ec's friendly use (just give me a month to test my installation and find any problems