The soundtrack is largely electronic and often upbeat, contrasting with the quiet ambient music used in the Portal soundtrack. A walkthrough to beat all the chambers in no more than 2 minutes (merits to MNC mascot) Chamber 16. On the Portal 2 blog, the Soundtrack is marketed as an 'aural stimulus package' developed by Aperture Science featuring fully mixed MP3 tracks (where Mike Morasky is credited as 'Aperture Science Psychoacoustics Laboratory') alongside ringtone versions for Android and iPhone. Video tutorial to complete Portal Reloaded Chamber 15. On September 24, 2014, to celebrate the release of Steam's Music Player, Valve re-released the Soundtrack as free DLC available to those who own the base game. On July 1, the second volume of the Soundtrack was released, while the third and last volume released later that year on September 30. On May 25, 2011, the Portal 2 Team released for free the first volume of the complete Soundtrack, titled Portal 2 Soundtrack: Songs to Test By, on the official Portal 2 blog.

Test chamber 15 portal