Good idea that's hindered by a lame campaign.
Well, that statement is a lie, because despite how much fun this game is it still has a few flaws. For starters, the single player campaign is terrible. There are "cutscenes" but this is nothing more than 3D fighters standing there and talking. Yes, you can relive some of the classic battles, such as Goku vs Freiza and Cell vs Gohan, but the steps you must take to get to those battles is really lame.
You have to endure battles with countless enemies and go through the story lines of Dragonball Z movies that no one cared about. Perhaps the most annoying thing is how your victory in the battle determines nothing in the storyline. For example, in the Feiza saga you'll have to fight Freiza about 10 times. Even if you do whoop his ass the first 5 times you still have to keep fighting him. It's really disappointing when you win a battle but the storyline tells you that actually you were barely able to survive.
Sadly, the single player campaign is a must if you plan to unlock all of the characters. That all being said, the rest of the game is actually quite fun. Combat is very fast paced and in depth. A person new to the game can start having fun in about 10 minutes, while a veteran can still have fun after playing 30 hours. The neat thing about the game is that you can do just about anything they could do in the show. For example you could launch a Spirit bomb that, if successful, can really damage your opponent and even change the entire battlefield/ignite the land on fire. the motion controls for the Wii are decent but not as in depth as you'd like. Still, the fact that you can unleash a fireball by pretending to shoot one is awesome.
On a side note, the graphics are great as well and all of the original voice actors are present. Although there's a bland sense of presentation in the campaign, the game play and fights are very well presented.
All in all this game is good if anything else. If you're a fan of the series you'll love this. If not, well rent it and see. At 50 bucks its not worth it, but now that it's price has dropped to 20 it's well worth the money. At the very least, you should try out this game