Not sure if this has been asked anywhere else, but do the rules allow showing the game inside of a fake Gameboy-like console?

Was thinking it'd be a cute intro to show a cartridge load into a fake console. The game on the fake screen would match the rules, but the "banner" as it were wouldn't and would be animated. I'd also include other viewing modes without this function for completeness.

I think this answer from the FAQ might answer your question :)

Can I use a resolution which isn't 160 x 144?
You may use a smaller resolution if your game engine of choice does not produce 160x144. The play area should fit within a gameboy screen. Black bars or 'super gameboy' frames around the outside of the gameplay area are fine.