Companion Cube Pin
- [Undocumented] The Companion Cube Pin was added to the game.
- The Companion Cube Pin was made giftable.
- [Undocumented] Players who earned the Companion Cube Pin for pre-purchasing Portal 2 had their pin upgraded to Genuine quality, and it became tradable.
- Added the Limited attribute to the Companion Cube Pin.
- The Resurrection Associate Pin uses the same model as this item.
- Four Vintage Companion Cube Pins were given to play-testers of Portal 2 at PAX 2010 prior to the item's official release.
- Team Fortress 2 - Companion Cube Pin
- "Thanks, Valve! (Or "Why Valve is fucking awesome.")", post by Dacvak on /r/gaming on Reddit, November 30, 2010 (TF2Items link).