Lego Star Wars: The Complete Saga has 36 main story levels. The total comes from six chapters for each of the six Star Wars episodes covered by the game, spanning The Phantom Menace through Return of the Jedi.
Released in 2007, The Complete Saga combined the content of Lego Star Wars: The Video Game and Lego Star Wars II: The Original Trilogy. It also added new material, including the previously omitted levels “Anakin's Flight” and “Bounty Hunter Pursuit.”
The number 36 refers specifically to the main story levels, which is the figure normally intended by this trivia question. The game contains additional playable content beyond those chapters: 20 Bounty Hunter missions, six bonus levels, and arcade games. Counting every activity would therefore produce a different total.
Players can replay the story chapters in Free Play after completing them, using characters with abilities unavailable during the initial story run. That replay system is one reason the game offers considerably more gameplay than its 36-level headline suggests.