Hi! No I meant within the current constraints of the Arduboy, this might just be possible.
You might be able to get away using the USB port and
Serial to load the game world from an external source. That might be a computer connected to the internet (online RPG, whaa!) or a tiny extra device with a bit of memory, plugged into the USB port, flashed with a "game world extension", kind of how old-school game cartridges worked.
This is still a concept though, but once the source code is up I'd like to have a stab at this, so let me know!
PS: @bateske do you think such a cartridge-like device could be created for extending the Arduboy? I'm mainly concerned about power (while operating from a coin cell).