The idea is to use a 2.5" LCD augmented with a lens and play third-person or top-down games where it doesn't matter losing some information on the sides. I will add a 4" IPS screen on the opposite side. And SWAP the controller to play on the screen you want
Finally I'm going to use two 75mm lenses superimposed at a distance of a couple of cm. I am waiting to receive a remote control type that mobile phones use to connect to the Raspberry Pi via USB.
As sound output I am going to use a USB-3.5 minijack converter connected to the Raspberry Pi3. The mini Jack installed on the unit itself causes a lot of interference. I have followed the tutorial in this video to configure the USB output before that of the card itself.
I bought this lens to see its effect and even though it appears in the product description x10. I have to move the lens too far away so that it covers the entire diameter. I have to try another one