I found the requirements for MakeCode Arcade, and it would be nice to make it also work. My current prototype fails to meet several of those requirements, but they seem to be pretty arbitrary:
No "menu" button. I suppose I could add one.
No "reset" button. You reset the board by shorting two pins on the connector, and I think that is sufficient.
Mechanical on/off switch. They want to use deep sleep mode instead, but that is not supported by CircuitPython.
No sound. That is an intentional decision on my side, both to cut the costs and to prevent noise during workshops and classes. They require mono sound with an amplifier on the DAC pin, but I have that pin broken out on the connector. I could have an additional add-on board with an amplifier and a speaker, if I really wanted.
All in all, apart from the missing menu button, I don't see a technical reason why it shouldn't work the way I have it now.