Crysis 2 has an interesting take on shields and invisibility. Perhaps a spartan III game one day could run with the idea. Spartan III had less shields/armor and greater stealth/invisibility correct? What I like about the invisibility is that you can see the color difference on a wall if you watch closely or you can spot shadows and I like how you take increased damage if someone sees you while invis and lands a shot. Prevents careless players from doing well with it.