Gordon Freeman’s neutrality of dialogue and lack of overt personality within the game do not make him a non-character, but are in fact his strength. His lack of preconcieved identity provides not a single barrier with which to distance him from the player’s own personality, making him a blank canvas on which they can imprint their own values and outlook. Valve have even made it impossible for the player to ever see Gordon from a third-person perspective, either through cut-scene or reflection, meaning that in no instance does the effect of seeing a character who does not look like themselves pull the player out of the experience of ‘being’ him.
But Valve have also made sure that Gordon does not remain an empty set of gun sights. Rather, Half-Life 2 uses purely the events of the game to communicate emotional responses to the player directly, cutting out the middle-man of pre-scripted in-game character response. Players are free to respond to the events they experience in any way which is natural to them, and that subjective element is key to the whole process. Through their own personal interpretations and responses to what is going on around them, the character of Gordon Freeman incubates in the real world inside the player’s head rather than on-screen. As the story builds and progresses, Gordon and the player blend and evolve together in a completely natural reactive way as they are affected by the same events for the same reasons. The player is not portraying Gordon Freeman. Gordon Freeman is portraying the player. He’s as layered and complex and as individual a little snowflake as you are, so you might want to rethink those accusations of him being boring unless you’re pretty dull yourself.
While Valve do not in any way manipulate the player’s development of their own personal Gordon, every major phase of Half-Life 2 is structured in a way which is powerfully provocative in bringing a gut emotional reaction out of the player, and it is those reactions which forge the player’s Gordon personality every step of the way. Far from using a mere collection of happy and sad events just to make the player feel something, the journey is structured in a way which builds a progressive and profound character development in the player’s internal Gordon through his experiences. What’s more, it is one which mirror’s the real-world player’s experience of working through a videogame.