It seems like the primary purpose of Naruto: Ultimate Ninja Heroes is to bring Namco Bandai's snappy PlayStation 2 fighting series to the PSP--no more, no less--and to this end, it is mostly successful. It offers some superficially different gameplay modes and introduces team-based combat, but neither really changes the feel of the action. If the Ultimate Ninja games didn't do anything for you on the PS2, the arrival of Heroes on the PSP isn't going to have much impact, either, though it's sure to please fans.
Naruto: Ultimate Ninja Heroes is a one-on-one fighter that favors speed and simplicity over depth and precision, and the controls feel comfortable on the PSP, though that's not to say there isn't some nuance to it. You've got a single attack button that you can easily string into a few different combos, as well as a projectile attack button that you can bolster with different types of shuriken found on the battlefield. The jump button proves most versatile, allowing you to easily double-jump, quickly dash toward your opponent, and instantly teleport yourself between the two planes found in each battlefield.
More often than not, though, the key to victory lies in your chakra attacks, which are fueled by chakra orbs dropped by your opponent whenever you finish a successful attack. Once you've amassed enough chakra, you can activate it with a single button press, after which you have a few seconds to connect with your enemy. Succeed, and you'll watch as a hyperstylized attack sequence unfurls, usually taking a huge swath of your enemy's life bar with it. Unlike its predecessors, there's no interactivity once you've launched your chakra attack, which kind of takes you out of the action. Furthermore, there's only one chakra attack per character, which means you'll see the same protracted sequences over and over again. There's a grand total of around 20 characters to play as, and though you might notice some differences in speed and attack strength, they all basically use the same controls.
While most of the combat basics should feel instantly familiar to established Ultimate Ninja fans, the big twist offered by Heroes is the introduction of team-based action, which is central to the heroes mode, where you'll fight against increasingly challenging opponents. The mode is divided by difficulty level, with each level consisting of a set series of fights. You can choose from an established three-person team of characters, such as Team Kakashi, Team Guy, Team Kurenai, and Team Asuma, or you can build your own custom team. You also choose the order they'll fight in, which doesn't really matter at first, but since your team's health and chakra levels carry over from one fight to another, spreading the load becomes a factor.
Based on whom you choose, you'll have access to unique performance modifiers and power-ups that you can apply before the fight starts. Like your fighters' status, the number of modifiers and power-ups you have carries over, which adds a little strategy to when you choose to activate them. Each battle in the heroes mode comes with optional win conditions which, if met, will earn you points that can be used to juice up your characters' stats, though these performance-enhanced versions can only be used outside of the heroes mode. The prematch power-ups and the way character status carries over are fun, minor additions, and they help balance out the now-hands-off nature of the chakra attacks.
Beyond the heroes mode, you can play the game against a CPU opponent or a live, local opponent, and the game additionally supports game sharing. There's also the promotion test, a series of ranked challenges that require you to meet very specific win conditions--beyond beating your opponent--before you're allowed to advance. This mode is tied to the heroes mode, since many of the scrolls you'll need to advance from one rank to the next can be earned there. While the action snaps and the modes of play are interesting enough, there's just not a lot to the game, a feeling that's exacerbated by the fact that much of the content has been borrowed outright from the previous Ultimate Ninja games.
A big part of the visual appeal of Ultimate Ninja on the PlayStation 2 lies in how those games capture the specific visual feel of the Naruto source material, something that Ultimate Ninja Heroes is mostly able to live up to. The characters look sharp, as do the environments, and the stylized visuals during the kinetic chakra attacks add a certain amount of punch to the action. Unfortunately, the shading effects that really helped define the look of the previous Ultimate Ninja games didn't make it to the PSP, which takes away some of the game's personality. The load times are a little harsh, but once a fight is up and running, there are no noticeable hitches, and there are moments when the camera pulls out so far that the characters are tough to make out.
The Naruto: Ultimate Ninja games haven't been terribly ambitious up to now, and with little in the way of actual, original content, Naruto: Ultimate Ninja Heroes feels even less so. That doesn't mean it's a bad game, it just means that it's not going to attract many fans outside its fan base.