Super Dragon Ball Z is a fighting game exclusively on the PlayStation 2 console. Typical DBZ games are of the fighting genre, but have their own style and system that sets them aside from traditional fighting games and almost creates its own mini-genre within a genre.
The game has its pros and cons. It was designed by the creators of Street Fighter II. The move system is nothing like the Budokai series. This one is much more like what you expect in other fighting games. Very complex combo system so it'll take you a while to master moves. Most stages are just about entirely destructible which is cool. The game is designed to pay homage to the manga series.
Its got 2 player versus mode so that's a bonus. There's no story mode. This game is all about fighting, but it does include an amazing customization system. Through victories you can collect dragon balls to then summon the eternal dragon and make wishes - new character outfits, new techniques, enhanced stats, etc. One cool feature is that you can inherit moves or techniques from other characters - so you can have a character like Chichi using the Kame Hame Ha wave or Android 18 using Yamcha's Wolf Fang Fist!
In terms of characters available, you begin with 13 - Android 16, 17, 18, Cell, Chi-Chi (adult), Frieza, Gohan, Goku, Krillin, Fat Buu, Piccolo, Future Trunks & Vegeta. King Piccolo, Majin Vegeta, Mecha Frieza, Ultimate Gohan and Videl are unlockable which gives you a total of 18 characters. As you can see, that's extremely limited considering these days DBZ games include over 100 characters.
The game also has transformations to super saiyan however they only work for a short amount of time. Overall its a fast paced game that no DBZ fan can resist and that really requires a lot more tactics and skill as opposed to the other DBZ games. Although its limited, I think Super DBZ is a definite must have for DBZ fans and I hope someday a sequel is made on a grander scale!