Nickelodeon All-Star is a chaotic platform fighter featuring a base roster of 20 characters from many Nickelodeon shows. These are iconic childhood characters, and many have iconic voices that fans look forward to hearing in-game as they play as their favorite characters.
Unfortunately, there is no voice acting in Nickelodeon All-Star Brawl. So while these famous characters battle one another, the battlefield will be silent except for the sound of slapping and smacking one another around. Victory screens and introductions are also eerily silent.
Developer Ludosity states in an interview with Game Informer that they prioritized making the game fun. They said, “Our focus was on creating the best possible gameplay experience for core brawling fans and Nickelodeon fans around the globe,” but added, "we will be reviewing all options, which may include adding VO down the road.”
So while these childhoods characters are oddly silent while fighting, they may receive a voice in a later patch. This could depend on how well the game performs in sales or fan outcry for voices to be added. Whether they will get their original voice actor or not is also up in the air. For now, Nickelodeon All-Star Brawl does not have voice acting.