From Wikipedia:
Players begin as a new student at Ridgeway who interacts with main characters Carly, Sam and Freddie at locations from the show, such as Groovy Smoothie, the Pacific Place Mall, and Carly's apartment. Gameplay is not the same as the original, with the player being able to create an avatar who can explore an open world from a third-person perspective. While the main cast of Carly, Sam, Freddie, Spencer, and Gibby are voice acted, the rest of the characters speak in gibberish.