This is an Anbernic RG353P running AOSP 12 Beta 1 from https://www.patreon.com/blackseraph
The landscape mode was forced by using a Chinese lsposed module. I tried lots of alternatives, but this is the only one that did exactly what I wanted: https://modules.lsposed.org/module/com.fankes.forcerotate/
I made a short video showcasing the experience of the game in landscape mode on this device, including all the menus. Some of the text is trying to escape the confines of the buttons, but everything is generally quite usable despite the unintended nature of it all.