That's such a classy Gameboy and screen color. Looks great. :)
Yes, that seems reasonable to "auto-resume" some time after power-on and idle (if there is an existing save state). Should be easy, I can look into it soon.
When you turn it off, do you pause or return to the menu first? It used to auto-save once a minute, but that was adding a lot of overhead due to the amount of data saved. So I changed it to only save under these conditions:
- The game board will be saved when starting, stopping or pausing