How to run Program on top of Kodi(RaspBian)

I am trying to launch retroarch from KODI

I am using Raspbian not LibreELEC.

I tried with this on command line(with kodi open):

Code:
kodi-send --host=127.0.0.1 --port=9777 --action="System.ExecWait('/home/pi/run_game.sh')"

inside the /home/pi/run_game.sh I have this:

Code:
/opt/retropie/emulators/retroarch/bin/retroarch -L /opt/retropie/libretrocores/lr-picodrive/picodrive_libretro.so --config /opt/retropie/configs/megadrive/retroarch.cfg "/media/usb0/TORRENTS/No-Intro/Sega - Mega Drive - Genesis/zip/Zoop (USA).md" --appendconfig /dev/shm/retroarch.cfg

When I run the kodi-send, retroArch open and run the game, but I can’t see anything because Kodi is on top of it.

Are there a way to put a retroarch window or any other program over Kodi, but keep kodi it running?
I do not want to quit and open Kodi every time I choose a new game.

If I exit Kodi and run the second command, I can play the game without problem.

ps: sorry for my english