Talk or not to Talk? The Question of Silent Protagonists
Having played through Uncharted 2's campaign, I must say - I really enjoyed listening to Nathan Drake talk. He's a very likable character; always sarcastic, spontaneously funny and serious when he needs to be. He fights for what the player believes is a good cause and comes off as genuinely endearing. Not to mention his voice acting was spot on.
On the other hand, The Prince from Prince of Persia came off as a straight-up asshole to me. He was most everything I could dislike in a guy - boisterous, arrogant, and womanizing. Most of his jokes fell flat for me. He would make petty jokes about important plot points, almost satirizing the entire story. It actually felt good to throw him off cliffs sometimes (though, to my disappointment, Elika will always save him).
Video game designers have been throwing around whether protagonists should talk or not ever since characters began to speak at all. In many game franchises the main character never speaks, even if everyone else around him does. In Super Mario RPG this is even used as a comedic device. In the early generations of games there was hardly any dialogue, and when there was it was never spoken by the protagonist. Of course, few games from the NES era could have what you would consider "memorable" stories.
Now that voice acting is commonplace in games we come to expect all the major characters to have dialogue, including the one you play. The problem with that, of course, is portraying a person you would not want to help out in the first place. When The Prince said something I would not want to say it bothered me; easy enough to ignore in a cutscene, but when he would start talking in the middle of traversing a level it would really get on my nerves. It detracted from the most important part of the game: the gameplay itself.
A good question to ask is why it was annoying - my immediate thought is that his attitude was flat out annoying. The larger problem with a dislikable player character is just that - s/he is a person you are actively portraying, playing the role of. Not many people would want to play an annoying protagonist; they end up being ignored and become a low point for the game. Take Final Fantasy X for example. The game generally got high marks for the mechanics and graphics, but the lingering taste it left in many gamers' mouths was the same - Tidus sucked. He was whiny, overly-emotional and a crybaby. His worst offense? The scarring memory that was the laughing scene that Crispygamer highlighted in their Great Moments in Voice Acting segment:
The problem is that a dislikable protagonist can really bring down the enjoyment of a game. In other forms of media the observer is purely a third party, so each character needs sufficient emotional display in order to be developed. In a video game with a lead character you essentially control their actions and identity; games with morality systems and dialogue options try to emphasize this further. Having a supplementary personality on top of the player's level of control creates an unnecessary duality in the character's persona: in a cutscene they will act certain ways and say certain things, but once the player regains control they again influence their actions and behavior.
On the flip side we have the silent protagonist. There is definitely an awkward or even humorous element to a story where everyone talks except the player, but it can certainly be utilized well. Half Life 2 has an excellent narrative that succeeds without a single cutscene or word coming from Gordon Freeman's mouth. It succeeds since it relies on Gordon's actions being louder than words. It lets the player fill in the blank words and emotion Gordon doesn't express. He doesn't need to spew over-the-top one liners during the hovercraft escape since if the stage succeeds in its design, the player would be saying them. Gordon saying them would just be redundant.
Another example is Shadow of the Colossus. The game manages to elaborate an emotional and powerful story with hardly any words at all. The haunting presentation and musical score told much more than words could. The most powerful scene to me was towards the end of the game. It managed to nearly bring me to tears, with not a word spoken (well actually Wander does say one word, which is the only word he speaks in the game besides grunts). I'll link to the scene, but please only watch if you've already beaten the game.
Games shouldn't have to tell you how to feel through the protagonist's words. The goal of any kind of media or storytelling is for the observer to draw their own conclusion. If the goal of a game is to immerse a player, any dissonance between their own feelings and their avatars' creates a lapse in their emotional investment. I read a forum thread not too long ago which was discussing why Link from the Zelda series always wins video game character popularity contests and stands out as an iconic figure. The best answer there was that "Link is the character that every player wants to be". His actions never differ from what the player wants to achieve, his emotions (or lack thereof) never override what the player wants to feel.