Just make sure you find a way to keep your pixels constrained to the enlarged pixel grid (as per the rules!) At this point, you're probably going to have to design your game unscaled, and then use the image API to upscale a portion of the game to fill the window... Bit of a pain, as you must manually keep track of your "gameplay view," but that's the only way that seems to work (thanks to NobodyX for suggesting it.)