Would it be better as just all of the set pieces or a big background magnet as well? If a background magnet, should it be just the sky? Just the sky and floor?

JoypadLad.com X SuperStickerClub.com

Would a magnet set where you can put pieces over a background image be cool or would it be weird with white outlines? Would it be better to try to make the outlines thinner and black (they'd still be a little thicker than the actual game)?