Portal 2

This page details one or more prototype versions of Portal 2.

July 28th, 2009A cereal factory?

2010#

February 4th, 2010Ugh - your hands are sticky March 18th, 2010 July 22nd, 2010As close as you'll get to an E3 build. August 30th, 2010Now with haunting potato noises. September 24th, 2010 September 28th, 2010 October 19th, 2010"My life is torture, please kill me." December 1st, 2010I wanna go to the Aquarium! December 3rd, 2010

2011#

January-February 2011The final hours of Portal 2. DVD Preload BuildMarch 9, 2011

CEG protected builds#

The Windows versions of these builds were compiled with Custom Executable Generation enabled, a DRM scheme used by Valve circa 2009-2014. Due to the way these were archived, they are literally missing chunks of the code and essentially impossible to run. The Mac versions still work however, as CEG is Windows-only.

April 12th, 2011Two builds were compiled on this date: one at 16:53 and another at 18:13. April 15th, 2011

Peer Review#

The work in progress builds for the Peer Review DLC released in October 4, 2011.

May 17th, 2011This build also contains an unfinished DLC 2 which is not related to the Puzzle Maker. It seems that it would've been a Singleplayer and Co-op DLC revolving around the paint gun, several new mechanics such as the Schrödinger cubes, Hot Potato which is a newer attempt at the futbol minigame, and the Reflection Gel. These were removed in the next build. May 31st, 2011 June 24th, 2011 July 21st, 2011

Perpetual Testing Initiative#

The private beta for Puzzle Maker was given to a few Portal 2 mappers to test out the Puzzle Maker and its features. Unfortunantely, the builds are protected with Steam CEG, so they are impossible to run. The Depot ID used for the testing is 841.

December 1st, 2011Two builds exist with the last seen day in timestamp. December 8th, 2011 December 15th, 2011 December 16th, 2011 December 23rd, 2011Two builds exist with the last seen day in timestamp. January 11th, 2012 January 12th, 2012 January 13th, 2012 January 23rd, 2012 January 24th, 2012 January 27th, 2012 January 31st, 2012 February 2nd, 2012 February 29th, 2012 March 2nd, 2012 March 9th, 2012 March 12th, 2012 March 21st, 2012 March 27th, 2012Two builds exist with the last seen day in timestamp. April 13th, 2012 April 20th, 2012 April 27th, 2012 April 30th, 2012 May 2nd, 2012 May 3rd, 2012 May 4th, 2012

Sixense MotionPack#

These builds were originally made available through an archive posted in the Portal Series Beta Research Discord server on November 9th, 2025, but can now also be found in the larger Steam2 archive. They date up to several months before the DLC's release.

March 9th, 2011 (MotionPack)The oldest known build of the MotionPack. Contains several cut maps and numerous differences in the used maps. May 5th, 2011 (MotionPack) May 6th, 2011 (MotionPack)A total of three builds were compiled on this date: 07:35, 10:27 and 19:40. May 14th, 2011 (MotionPack) May 20th, 2011 (MotionPack) June 7th, 2011 (MotionPack) June 8th, 2011 (MotionPack)Two builds were compiled on this date: one at 00:25 and another at 19:01.