The V40 Max is a new and affordable gaming handheld designed to play a wide variety of games, not just very old titles. It features joysticks as well as shoulder buttons. The model's design is basically similar to a Game Boy, at least in terms of the display layout.
Guess you are the crowd that’s being catered to with emulators that prioritise accuracy. So you should look for that label when selecting an emulator.
Reminds me of Tiny Toons for Gameboy. My brother would tell me he had a hack to get to the final cutscene. He’d do something magical and it’s start playing. And although I knew both the intro and outro of that game by heart I couldn’t figure out that he was just showing me the intro, because the game would restart when you pressed all (or most) buttons at the same time.