In general, the functional edge of an object should attract more attention than the surface. right now the faces of the boxes demand a huge amount of attention, but the actual playing field is ambiguous.
Gameboy colors are going to further frustrate your attempts to rectify and i'm not sure what they bring your project other than a false/forced sense of nostalgia. If you like the idea of lower color counts, cool, more monochromatic, cool, more green, maybe, but why make a real project based around specs that aren't lending you anything? that sort of thing is best saved for mockups and exercises and other smaller investments.