The R36S is not meant to emulate the Saturn well. See here https://retroabxy.com/r36s/
At best you can play some games but you won't for most. If you want to emulate Saturn you gonna have to pay much more than $40.
The problem is there aren't too many devices 4:3 devices between 4 to 5 inches. Shouldn't manufacturers already understand that those who are into retro gaming now are in their late 30s or early 40s now? Haha