@marcoabm there is a way to do this so that someone has to press the back button (usually coded as B) to get out of the favorites list. I BELIEVE though I am not in front of my pi right now that if while in emulation station you hit the start key to get to the emulation station menu you have to change two options (btw I have this set up on my bartop this way for the reason you mention). First there is an option for start on system or something similar and you can choose “favorites”. This way when the pi boot it will go right to
Favorites. Then there is another option. It might be called quick system select or quick carousel or something. You can disable that and now someone can not switch systems by moving left and right they have to press the button to physically back out of the favorites menu and back to the top menu. I will try to find the exact name of the option later if you can’t find it.

EDIT: Ah! I found it online. It is in the emulation station menu as UI options, then “quick system select” you want to disable that. Also, if you want to go super extreme and don’t want to leave it as just difficult to go to the other systems but rather make it absolutely impossible to do that; you do the foregoing two steps and then also edit the configuration file that is related to the actual control buttons for emulation station and remove the back button. I am not a big fan of that personally because I still like to be able to back out sometimes but if you really want to do that I have done something similar (switched the button used for menu and back in emulation station) so could walk you through it.