I have an older Bitt Boy in GB-like shell and it works quite well, it struggles a little with SNES. The battery is swappable but you'll get few hours out of it.

I have an older Bitt Boy in GB-like shell and it works quite well, it struggles a little with SNES. The battery is swappable but you'll get few hours out of it. Charges from micro USB. https://bittboy.com/ https://bittboy.com/