Halo 3: ODST is a 2009 first-person shooter video game developed by Bungie and published by Microsoft Game Studios. The fifth installment in the Halo franchise, it was released on the Xbox 360 in September 2009. From Wikipedia
The trailer’s ending features the ODST “Rain” sax motif over a rain-soaked city, signalling fans’ hopes for Halo-themed cosmetics on release.