The Analogue Pocket is a modern reinterpretation of vintage handheld gaming systems. It's unique from other handhelds (such as those made by Anbernic) in that the Pocket does not use software emulation. It uses FGPA hardware to fully replicate the original game as intended. It can run game cartridges, but you can also use the microSD card slot to run ROMs of games from tons of different gaming systems. I did that with the pupdate project.
It's a joy to use. I only wish I had sprung for one of their higher-end limited edition models made of aluminum.