The difficulty in making retro style (programming) hardware is that any technique you use to use to make it nowadays could be trivially be boosted to be much more powerful, sufficiently powerful in fact you could probably just run a software emulator for the thing.
I'm going the route of others with making a fantasy console, and will be content to run it on mobile platforms in an emulator, which is what happens with the pico8.
That said, I do have a half baked idea in my head to make something from a AtMega and an ESP32. If the higher clockspeed of the esp32 is enough to make it pretend to be a valid xram interface for the AtMega. Then output s-video out the DACs.
I'm going the route of others with making a fantasy console, and will be content to run it on mobile platforms in an emulator, which is what happens with the pico8.
That said, I do have a half baked idea in my head to make something from a AtMega and an ESP32. If the higher clockspeed of the esp32 is enough to make it pretend to be a valid xram interface for the AtMega. Then output s-video out the DACs.