There's a ton of gameplay packed into one small cartridge with Jump Superstars. It's a fun, albeit flawed, DS fighter.
One thing that those not fluent in Japanese need be aware of is that the game is incredibly text heavy. This isn't a traditional fighter; Jump Superstars has players assembling "decks" of manga panels that consist of Battle, Support, and Help characters. This deck appears on the DS' bottom screen, and players can tag team by tapping different characters. If your little pink-haired munchkin is taking a beating, call in a ninja task force to make with the stabbing. The problem here is that in order to build these decks, you must first assemble the panels, called "koma." This entails matching a character to an panel with Japanese dialogue. While the little kiddies across the Pacific'll probably have no problem with this, it's infuriating to those not fluent in Japanese or entrenched in shounen lore. Even as someone who can read Japanese, I couldn't always tell which characters belonged in what panel. It's a clever idea, but it ends up being arduous and time-consuming. There's a work-around to streamline the process, but it doesn't completely fix what's inherently flawed. The game would've been better off with a simpler system wherein players could unlock characters in already assembled koma. Otaku be warned; you will need a guide to navigate the deck building interface.
Keep that guide handy, because you'll also need it to translate the stage objectives. There is a huge offering of levels in this game, often centered around different comic series, and each level has a few optional objectives that ramp up the challenge and unlock more characters. This adds huge amounts of replay value to the game, and definitely keeps the formula from going stale. While this sort of replay seems a more temporary fix in place of real gaming depth, there's enough of it to go around that it really adds hours and hours of goodness to the game.
It's a bit more forgivable, then, that the features outside of single-player mode are lacking. There's no online play (understandable given the game's age), and while the player can set up computer opponents in Versus mode, they're simply too easy to be fun. They really pose no challenge, even on the hardest difficulty or grouped into teams. Jump Superstars is clearly not intended as a only a children's game, as it features series from many years ago and comparatively difficult single-player challenges, so it's a bit boggling as to why these multiplayer opponents are so easy.
Speaking of boggling, the sound is pretty awful. The music is repetitive, sound effects aren't terribly varied, and some voice clips might've been appreciated.
These are surface-level quibbles, though. Jump Superstars is a solid DS title that's worth picking up. Fans of Smash Brothers will feel at home with the simplistic control scheme, but will be pleased by the fair amount of depth present in the koma system. It can be an intimidating game at first given all the Japanese-text, but those who stick with it will be justly rewarded.