If you're making a portable you probably need something to watch it on. (Unless you want to guess what's happening in the game, but I wouldn't advise that) Anyway, this forum is your "Hacking a pocket TV/screen" one-stop solution. Share your experiences and knowledge here.
parkie, if you have a faint picture, in shades of black as you say, indicates too low draw in your batteries (I had this when experimenting with batteries) - you might have the voltage but not the power. See my previous post. You need power cells, photo grade, high NiMH.