I've heard a lot about these things, is it worth getting and is it like an emulator? And what kind of games does it run like any kind of retro/older gen stuff?

It’s wonderful! It’s not a typical software emulator, like a lot of the other retro handhelds. Instead, it uses FPGA hardware emulation. Plays GB, GBC, and, GBA carts out of the box, and OpenFPGA gives you access to pretty much every 16-bit and older console via roms.