This isn't really even a sequel.
The gameplay is simply, and immersive when you first start playing. The game isn't long but there are plenty of unlockable characters to get, and the fighting is pretty fun. But it has little innovation. We've seen tons of fighting games, tons of 2D fighting games, tons of DBZ fighting games. What makes Supersonic Warriors 2 so different from the rest? Nothing. It's not really even a sequel. It uses the touch screen little, only when selecting the fighter you are going to play as, and the courses you ar egoing to play in and the menu options. Other than that, you don't use the screen at all. The game is a tag-team game, so when one of your fighter dies you'll be another. You get three fighters to play as and you have to fight three.
The graphics are just above Gameboy Advance quality. They are 2D, and this probably could've even been a Gameboy Advance game. The music isn't really all that clear and repetitive with some of the songs.
Verdict: Overall Supersonic Warriors is a fun game while. it lasts, with little innovation and a weak graphics engine.