On the other hand, many cool games never made it to the PAL region, and a lot of PAL ports (and video releases) got technically botched in some way.
But, FWIW, I've been really happy with acmeplus's beta of Batocera Linux on my RG35XX+. My son and I have been taking turns playing through old gems like Pokemon and Aladdin on it, and I'm hoping to finally beat Final Fantasy VII one of these days.
By the PS2/GameCube/Xbox era most games were fine and PAL60 was becoming a thing anyway, but older than that and there’s a good chance the game just runs 17% slower due to the 50/60Hz difference, or has some weird letterboxing due to not accounting for 576 vs 480 lines.