There was a time when getting your hands on a Dragon Ball Z game was a special thing. They weren't as popular here in the States and releases of localized titles were nowhere near as prevalent as they are today. Perhaps it's time to long for those days of yore. DBZ titles are now coming out every couple of months and I dare say the market has become saturated.
The latest release is Dragon Ball Z: Tenkaichi Tag Team for the Sony PlayStation Portable. I have played through many DBZ games in the past and let me say that Tenkaichi Tag Team brings little innovation to the table. Sure there are online battles and yes the tag team element is more prevalent here, but the core gameplay and concept will elicit a sense of déjà vu in most gamers. It's been done before, and done better. I suppose if you're looking for some Dragon Ball on the go this game is a good option, but even then it's a bit lackluster.
As far as the plot is concerned, this is Dragon Ball Z. It follows the story from the anime from the very beginning and carries it quite a ways, never deviating from it. The tale of Goku and company is revealed through shoddy pieces of dialogue and occasional cut scenes. The result is an ineffectual way to relive the DBZ saga, but those who already know what is going on would probably just skip these pieces anyway. As long as players aren't using this to refresh their knowledge or learn about DBZ they should be okay.
The gameplay in Tenkaichi Tag Team is about as straightforward as you can get. It's a fighting game in its simplest form and the control scheme should be nothing new to returning players. There are attack, ki, dash, and maneuvering buttons that can be used, but frankly it's nothing so complicated or in depth as Street Fighter IV. The combat here is strictly broken down into two strategies: bash the attack button until your opponent is dead, or charge and release super power moves for the same result. Because of this, the gameplay is fun for a while or in short bursts, but anyone looking for a meaty or robust experience will be left out in the cold.
The Tag Team element works its way into the gameplay well enough, with the ability to pull off combo attacks as a team or switch characters. Be forewarned that the computer takes advantage of this as the difficulty spikes later in the game. Don't be surprised if you find yourself on the receiving end of a cheap unblockable string of attacks that destroy you in mere seconds. In this game it's par for the course, and that's really kind of a shame.