https://www.gamespot.com/articles/xbox-ones-new-game-pass-titles-for-september-2018-/1100-6461505/

It's officially September, and that means the next wave of additions to the Xbox Game Pass library is now available. There were 10 titles added to the catalog for September 2018, including some big first-party games such as Halo: The Master Chief Collection and Quantum Break. These add to the more than 100 games (across Xbox One and Xbox 360) that are already available in the library.

The Master Chief Collection, which originally launched in 2014, is the biggest Halo package ever released. It includes remastered versions of Halo: Combat Evolved and Halo 2, in addition to Halo 3 and Halo 4. All of the multiplayer maps for each game are also included. If you're playing on Xbox One X, the game looks better and loads faster.