I have, in the past, praised the first DragonBall game for PSP, Shin Budokai. Although DB Evolution uses the same engine, it feels like it's been dialed back a lot. Due to the fact that it's based directly on the film, the cast has been reduced enormously. No in-game transformations, no movie-esque versions of characters from the anime making guest appearances, and no chance of some of the more minor characters from the film making an appearance. I would have at least liked to have seen Ernie Hudson's character appear.
Since the action in the movie was likely less based on gigantic ki battles than its source material, these moves have also been reduced greatly. This makes for a better variety of attacks throughout the roster, including some impressive Super Moves, but overall, it doesn't feel right for this engine. The engine was MADE for mega projectile battles galore. If they really had to make this game, they should have given it a more traditional control system, like Street Fighter or KoF.
Though the character models are bland and muddy, some backgrounds stand out as cool-looking. The in-game portraits more or less look like rotoscoped versions of the actors (with a few weird snafus here and there like Piccolo looking up with his head straight all of the time, or the chunky loading screen Goku), but the in game fighters don't look a thing like the actors. Characters are unrecognizable to fans of the series, although that's as much the movie's fault as it is the game's. They could have at least given unlockable costumes for the characters that more closely resembled their anime and manga counterparts - like giving us a bald, bearded Roshi instead of some Chinese dude on vacation.
Arcade mode is serviceable, giving each character a rudimentary goal to chase after and allowing the player to fulfill this. It's story mode that falters. I'm guessing it more or less follows the movie pretty closely, and that's where it's boring. The writing is horrid (especially compared to the punchy dialogue in Shin Budokai) and is very long-winded, with several times more dialogue between battles than a fighting game should have. Furthermore, instead of being able to save after every battle, one can only do so after ever "act", some of which consist of two or three fights. This is very inconvenient for a portable game. Also, the final character to unlock must be done after achieving all "A" ranks of higher in each chapter. While this is not hard to do, it is impossible to do in one playthrough, as not all of the fights in the chapters are unlocked the first time around. Although this might be a source of added play value for some, it can actually be a source of irritation, especially in a game this clunky.
DragonBall Evolution is the exact opposite of its title, in the fact the it fails to even match a game using the same engine, released three years prior.