HELLO
Go to emulationstation menu > game options.
or edit recalbox.conf
## Default cores for RPi3
snes.core=snes9x_next
gba.core=mgba
mame.core=mame078
nes.core=fceunext
delete others lines.
https://github.com/recalbox/recalbox-os/wiki/recalbox.conf-(EN)