Developer commentary

Commentary Notes are spinning talking notes that the Valve team talks about how or why they made a map, an enemy, a character, or a story-line. The commentary notes also talk about what happened in the earlier versions of areas. To listen to a commentary note put you're cross-air on the floating commentary note and press the Used Key (E is default). To stop it, press the used key on the note again. Sometimes the notes could take control of the game.

People of the Valve Team you hear

 * Gabe Newell

Triva

 * Gabe Newell is the one who starts all the commentary's in the game.
 * The commentary's all started in Half-Life 2: Lost Coast, but then they put them in Episode One, Episode Two, and most likely Episode Three.
 * Commentarys were also put in Portal and Team Fortress 2.
 * In Portal, one commentary said, "This first portal game, doesn't explain it all.", which means there is going to be a Portal 2.