The three simulators by @bubble2k16 (VirtuaNES_3ds, temperpce_3ds, snes9x_3ds), is definitely the best simulator on the 3DS, RetroArch with this can not be compared, I have abandoned it.
when VirtuaNES_3ds support Map252 ? I play "San Guo Zhi (Ch).nes" with VirtuaNES_Plus, it is ok...