said customers would be happier with a new Half-Life game delivered in a shorter time rather than "waiting six years for another monolithic product". In February 2006, Valve announced a new title for the expansion, Episode One. In May, Valve announced that Episode One was the first in a planned trilogy of episodic games to be released over the following two years. Newell said he considered the trilogy the equivalent of Half-Life 3. According to Newell, whereas the original Half-Life (1998) saw the G-Man transform Freeman into his tool, and Half-Life 2 saw Freeman being used by G-Man, the episodes would see G-Man lose control. While the plots and dialogue of Half-Life and Half-Life 2 had been written solely by Marc Laidlaw, the Half-Life 2 episodes were written by Laidlaw and new employees Chet Faliszek and Erik Wolpaw. Valve's focus was character development, particularly that of Gordon's companion Alyx, who accompanies the player for almost the entire game. Walker said: "It's kind of ironic that despite so much of the theme of Half-Life 2 being about other characters and other people, you spent most of the game alone." Because of Alyx's significant involvement, Valve made modifications to her AI that allowed her to react to the player's actions. Changes include commentating on objects the player manipulates or obstacles they have overcome. She also acts as an essential device in both plot exposition and directing the player's journey, often vocalizing what the player is required to do next to progress. The developers explained that a large part of their focus was creating not only a believable companion for the player, but also one that did not obstruct the player's actions. They wanted to allow the player to dictate his/her own pace and method of overcoming any challenges faced without being hindered. This meant that Valve often had to scale back Alyx's input and dialogue during the player's journey so they would not feel pressured to progress and consequently object to her presence. The developers also placed what they described as "hero moments" throughout the game, which allow the player to single-handedly overcome obstacles such as particularly challenging enemies, during which Alyx takes the role of an observer and gives the player praise and adulation for their feats. The game was extensively playtested so that Valve could gauge its effectiveness and difficulty. Episode One was made with an upgraded version of Source,