In early game development, pre-production art tends to start with various designs for vehicles, space ships, battle suits, and things of that nature. People tend not to be satisfied or confident with those early designs, and pre-production often gets excessive.
In regard to character, combat suits and the like are the industry's favorite theme, and they're put through hundreds of designs as though product sales depended entirely on that. But how much of that pre-production time is spent on what's inside?
In approved concept art, usually we see fantastic costumes, accessories, and cool tattoos. But the drawing of the human itself often remains a stereotypical archetype. This is understandable because first, the characters' actual roles in games tend to be stereotypical, and second, it's not usually the concept artist's job to delineate the nuance of the human inside the combat armor.
Unless you have live casting, nobody really knows who the character is until a production artist starts modeling. With this kind of setup, there isn't much of a chance to find out the bare attraction of these characters.
Only a character with soul is capable of telling a good story, or delivering a message. Without real characters, the whole product winds up being an empty killing experience (although that is often all the game calls for). Establishing the character inside the suit is essential if you want to create products that have a lasting effect on players, and on history.
Concept art is full of visual language -- not only costume designs like helmets, mantles, jet-packs, artificial muscles and jewelry, but also scars, tattoos, pimples, and even a five o'clock shadow. This is all common language to provoke familiar ideas.
But organic objects are very complex, and especially when looking at human beings, our minds are capable of differentiating a lot more than simple visual language. The pointy ears and hairstyle of Dr. Spock from Star Trek are visual language tropes. That's very good costume design, and everybody remembers it. But that does not mean anybody can play his role as long as the body type is similar.
Leonard Nimoy (from the original TV series) and Zachary Quinto (from the new Star Trek movie) are human beings, and our brains are capable of reading more information than just those visual language identifiers. On the surface, it's easy to tell them apart with a few words. But it's very challenging to describe the specific face shape or nuance that makes up Leonard Nimoy or Zachary Quinto's Dr. Spock (see Figure 2). It would probably require a great author to describe it in words.
Figure 2: Here are photos in which all obvious visual language has been hidden. Makeup is another example of visual language. For instance, almost every one of Marilyn Monroe's facial features has become iconic.
Likewise, it requires a great artist to describe in art. What makes a human character human is those non-visual language elements. Typical game productions don't pay much attention to that.
If a particular game requires that players slaughter a bunch of enemies, there needs to be a reason. For example, the main character hates aliens because he saw them kill his parents. That is enough motivation to inspire the player to kill. In order to make it a proper story though, it needs one more step.
For example, the player killed countless aliens in order to take revenge for his parents. However, he discovered the aliens have a good side, through a relationship with a particular alien that changed his views. The alien became his close friend. Regular video games have this level of story at best.
In order for the audience/players to really feel emotionally involved with the story, we need to go one step deeper. For example, the main character wants to say he hates aliens, because it helps him stand out among those who favor them. In truth, he's not really sure whether he hates them.
One thing he is certain of is that it cheers him up when he gets attention from everybody after killing aliens, and he can play the big outlaw. He likes it. It makes it easier for him to get girls. He gets excited when he tells people his parents' sad story. That extreme delight comes to the surface, and a subtle smirk crosses his cheek.
And because he tries to prevent the expression from surfacing, an odd strain appears on his face, making a nice agonizing effect. He is not always happy. He is worried that he may have to continue being this way for the rest of his life. He is tired from pretending to be someone that he is not. Deep inside, he's actually scared when he looks down the sights at an alien.
Then, a strange alien appears in front of him. It acts differently, getting attention with a divine messiah-like quality. Our hero realizes it's a good time to change his character back to who he really is. This way he can return to being a regular person without having to expose his doubts. He has saved his pride and lived happily after. This is character development. We need to understand the inner character beneath his surface persona.
Finding flaws in your characters can bring them away from a false perfection, and creates great intimacy. Asymmetry is the typical method. The human face is not symmetrical -- making the eyebrows unbalanced, or making one cheek sag compared to the other side, or even adding a distortion of the entire skull -- these little things bring surprising intimacy.
Little pores opening on the tip of a pretty woman's nose, a belt of fat that appears under the jaw line when a person looks down, or a belt of fat over her pants line when she leans over, these things add some idea of who the character is.
Yellow stained teeth? One tooth missing? One cauliflowered boxer's ear? That's the typical method of adding imperfections in games, but really it's just simplistic visual language. Certainly it helps describe the role, but it does nothing to add real character depth.
These sorts of tropes come from just lazily adding random details on characters, such as pores, or wrinkles on the lips without reason. This only serves to divert the audience's eyes from the character itself to unimportant details -- unimportant because those details aren't there to convey any particular piece of the story.
For example, if you add realistic wrinkles on a character's lips, and it could communicate the idea that the place is pretty dry or the character is tired. This represents a failure if that is not the message that you wanted to convey. Every tiny element should be part of the final message.