This was pretty freaking cool as it goes. I really liked the idea of controlling the character in the game by using other games. That was super neat! I really would have liked to see more distinction between the puzzles, as in, making it very clear as to which cartridge to use. I went through the whole game with only one... but maybe they're all able to do that? I think this just needs a bit of polish in level design and it'll be really amazing.
Overall, super cool game!