Shadow Boss Showdown is the sixth level in Battletoads & Double Dragon: The Ultimate Team.
Our heroes return to Earth after their epic journey in space and land near the basement of an abandoned building where the Shadow Boss awaits them for a final match. The place is almost devoid of furniture, only lamps can be seen hanging from the ceiling - the player can cling onto these and destroy them to reveal power-ups.
Guidos and Walkers reappear in this level, although they are merely filler preceding the final showdown against the Shadow Boss, who by the way, can be seen stalking them along the columns in the background throughout the level. As usual, Walkers will leave one of their legs behind after being defeated, which the player can arm themselves with and easily poke Guidos into the ground until they fall through it. Not long into the level, the Shadow Boss will finally show up and challenge our heroes.