I like the game boy design it was cool. I had someone on my course who did a similar thing one. It would of been cool if they were animated so if you press Q you see the A button go down or something.
I think with the design concept projectile direction should of been dependant on the movement direction. As the whole game boy presentation kind of fails when you add an imput like the mouse location that cannot be linked to a game boy.
I think the player should of moved a little faster. Like in pac man the player moves faster than the ghosts its only when the player kind of seconded guesses themselves that they loose that advantage, something to consider.
This was a cool idea though would love to see to fleshed out.