There are plenty of games at E3 that weren't announced ahead of time, which gives a sort of treasure hunt aspect to the show. At Namco Bandai's booth, one of those games was Dragonball: Revenge of King Piccolo.
This Wii exclusive title follows Kid Goku (the first time he was a kid, not that other time) through the story of the original Dragonball series. It's a 2.5D sidescrolling beat-em-up. The engine is 3D, so Goku has a free range of movement, but the game limits him to a thin track, making it feel and play more like a classic beat-em-up.