Punch Time Explosion doesn't just take inspiration from Nintendo's Super Smash Bros. series. Rather, it's as if Dexter, Samurai Jack, and a bunch of their Cartoon Network buddies staged an invasion to oust Mario, Link, and the rest of the Smash Bros. gang from the land of zany multiplayer brawlers and claim the territory as their own. The Cartoon Network crew makes a spirited effort, and they give Punch Time Explosion plenty of personality. But beneath the superficial and short-lived pleasure of seeing Blossom and Ben Tennyson battle each other in Foster's Home for Imaginary Friends is a game that's shallow in multiplayer and frustrating when played alone.

Like the games that it imitates, Punch Time Explosion is a fighting-focused party game in which up to four characters clobber each other on a 2D plane. There are a total of 18 playable characters, if you count duos like Billy and Mandy, which can only be played together, as a single character. As you take damage, a number displayed as a percentage increases, and the higher this number gets, the farther you're liable to go flying when hit. You lose a life when you're knocked from the stage or fall from it. Each character has standard attacks and a number of signature moves at his or her disposal, as well as a special attack that can be performed once a meter is full. A variety of weapons--wrenches, flyswatters, magic wands, and so forth--spawn frequently, and if you're quick enough to grab them before an opponent does, they can significantly increase your power. In addition, special items show up that, when collected, summon non-playable Cartoon Network characters like Johnny Bravo and Mandark to lend you a hand for a short time. The playable characters exude all the charm of their TV selves; Flapjack's absent-minded, goofy grin is infectious, and Buttercup's glare tells you she means business. But a small number of voice samples that repeat much too frequently make the game's sound design grate; hearing Ben Tennyson exclaim "I should have picked a flying alien!" for the umpteenth time as he's sent soaring off the field in defeat may push you to turn the voices off altogether.

The environments in which you do battle contribute to the craziness. One arena has you fighting on the rooftops of Townsville while a giant robot smashes the buildings under your feet. Another finds you in the mouth of a giant whale who sometimes belches huge amounts of water and dead fish into the sea, threatening to expunge you as well. The result of all this is a chaotic game in which the unpredictability and zaniness generate some short-term fun as you discover what happens on the various stages and what the various items and supporting characters do. But whether you're playing against CPU opponents or friends, this chaos also makes it difficult to take much satisfaction in victory; so much happens all the time that the ultimate outcome seems as dependent on chance as on skill. You can opt to play with fewer items or no items at all, but stripping away these distractions only makes it more clear that the underlying combat is shallow and that attacks have no sense of impact. Characters tend to come together and dish out their attacks willy-nilly until one is sent flying.

Punch Time Explosion is at its best in Story mode, but even here it has some serious problems. An evil force is corrupting the universes of numerous Cartoon Network characters, providing a fine excuse for the Powerpuff Girls, Numbuh One, Dexter, and a bunch of other CN stars to band together and battle evil. The enthusiastic and funny narration by a CN voice-over guy who just wanted to relax and enjoy some cartoons on his day off lends the story an authentic Cartoon Network soul and prevents the adventure from feeling like a hollow licensed cash-in. Platforming takes priority over punching here, and bounding across chasms and over hazards with each character's double jump is pleasant enough. Or at least it usually is; some sections crank up the challenge in ways that only result in frustration. For instance, at one point you must make your way across a series of floating barrels that have a tendency to spin when you land on them, making it overly difficult to get your footing and make the leap to the next barrel. What makes this and situations like it doubly irritating is that losing all of your lives often results in a significant setback, requiring you to repeat minutes of easy gameplay to get back to the tricky bit.

Your side-scrolling escapades are also frequently put on hold when you're required to defeat a number of small-time bad guys or a single, more powerful cartoon character. These turn out to be some of the worst moments of Punch Time Explosion's Story mode, since they can almost always be won by repeating a specific signature move over and over. On occasion, you're required to protect a character as you defeat 25 enemies, a situation that encourages you to rely on this tedious but effective approach to knock the bad guys away from the clueless and vulnerable character you must keep safe. Other diversions also crop up from time to time in the form of basic first-person on-rails shooting sequences, mine cart levels, and the like, and these are more welcome, preventing the platforming from growing stale.

Punch Time Explosion supports local wireless multiplayer for up to four players. Unfortunately, there's no online support, so unless you have a bunch of friends close by who own the game, your opportunities for full-featured four-player mayhem are limited. There is a download play option that lets up to four duke it out with a single cartridge, though this option limits the number of characters and has only one stage on which to do battle. Frustratingly, over half of the game's 18 playable characters and 20 battle stages are locked at the start, so there's a good chance you'll need to sink in some time before being able to beat up your friends with your favorite character or in your favorite Cartoon Network locale. Since the characters are the game's greatest asset, it's disappointing that so many of them are unavailable at the start. Punch Time Explosion has a host of cool characters, but without the support of exciting gameplay, their presence can only benefit the game so much. Unfortunately, like a cartoon starring your favorite superhero that doesn't make the most of his powers and personality, Punch Time Explosion leaves you disappointed.