There are good games, and there are bad games. Then, there are grade-A embarrassments. This falls under that category. An open world DBZ game is a great idea. But first you have to get it right. Trust me, they epically failed at this one.
The melee fighting is awkward, the energy attacks are all similar for each character, and there is no charm to this game at all. The flight mechanic is one of the worst I've seen (ranks just below Sonic '06 Tails standards). Having a height limit after jumping off of a platform is flat out idiotic.
The boss fights are repetitive and boring. The available characters all play the same way. You shouldn't have to make continuous melee combos in order to build up energy to transform into a super saiyan. How does that even begin to make sense? The Budokai series got it right, so why is there a problem with this game?
Bottom line, ignore this game like the plague. It shouldn't have even been released to the general public.