Goku and friends rock no matter where you put them.
1. Media Exageration. The whole "Over 120 characters!" hype is only half true. In reality there are only about 50-60 (yeah, "only") characters, and they count each alternate version and transformation as one. Like Gohan. You've got Kid Gohan, Teen Gohan, Current Gohan, and Ultimate Gohan. Plus, there's Sayaman, and all of the Super Sayan transformations. Another example is Frieza, who has four forms, each counting as a different character.
2. Level system. The characters all have "levels", and unless you give the one you're currently controlling Z items (stat boosting items) it's always going to stay at level 8 (for you. Chances are, the guy/s you're fighting will be at least 20 levels higher than you). Still, that poor A.I. makes up for it, allowing you to controll a level 8 guy, and whipe the floor with a level 60 guy.
3. Giant Monsters. When you're fighting a giant monster (like a Sayan when it changes into an ape), 75% of the techniques you use to win won't work, and you'll have to come up a new way to win, while trying not to get your brains blasted out by the giant fist that causes a ton of damage. The worst part is, you never unlock these things, so you never get to take Ape Gohan or Vegeta out for a spin.
4. Weird Special Controls. A lot of the time, when you're trying to perform an action that leads to something awesome, it won't work. An example is Goku's Ultimate Blast; Spirit Bomb. First, you have to perform some weird move that doesn't do anything. And half the time, even when you're qualified to do it, it won't work! Another thing is when you're trying to transform into a stronger form. Half the time, even when you meet the qualifications, it won't work for some reason!
Okay, I've stopped complaining.
Good things.
1. Cast. This game has everyone a diehard DBZ fan could ask for in it. From Majin Buu to Pikkon, there's a cast of characters that you'll appreciate even if you only recognize a couple of them. You can play as most of them too. So if you like Hercule, you can play as him. (Warning: Do not play as Hercule unless the guy you're fighting stays totally still or you give him a ton of items.)
2. Fully interactive environment. This game is very good with the destructive environments. If you Kamehameha Krillin, and send his flying into a skyscraper, it will level the skyscraper. The environments serve a purpose too, as destroying stuff occasionally reveals Dragonballs. (Hint: When fighting in a city, prolong the fight and destroy everything, 4 out of the 5 Dragonballs I've collected were found on top of the rubble of leveled houses.)
3. Good moves. For the most part, the characters all have really good attacks. And the ultimate attacks are sure to please you with their awesome animation sequences. Some really good attacks are there too, like Gohan's Dragon Punch (when he's a level 3 sayan) and (Scouter) Vegeta's Dirty Fireworks (I don't know why it's called that, but I only noticed the fireworks part.)
4. Good Controls. The controls on this game are a little annoying on occasion, but for the most part, they're great. Even really complicated moves are relatively simple to remember, because chances are, you're going to use them a lot.
Overall, this is a great game for DBZ fans or fans of fighting games. If you don't like either, why'd you buy it? Still, I think it rules.