The concept of looking younger than one's age should dictate, particularly as it is used in fiction, is often a means to allow characters lifespans that extend beyond the real-life norm. Characters may have a greatly reduced aging process that causes them to age only a few years over the course of many, or perhaps bring a halt to the aging process altogether. Though there are real-life medical conditions that can affect the normal aging process, the most common methods as found in video games, if they are explained at all, are generally brought about by means of science fiction or fantasy.
Below are some examples of characters that are in actuality much older than they appear.
When first introduced in Parasite Eve, set in 1997, Aya is a twenty-five year old police officer working for the New York Police Department. However, the awakening of mitochondria in her body at the game's start unleashes new powers and abilities within her. In The 3rd Birthday, which takes place in the year 2013, Aya is once again the main character, yet she still appears as young as she was in the original Parasite Eve due to the effects the mitochondria had on her body.
Vincent Valentine of Final Fantasy VII and Shelke the Transparent of Dirge of Cerberus were both victims of Shinra experimentation that caused their aging processes to halt completely. In the present day of the Final Fantasy VII universe, Vincent should be an old man and Shelke should be a healthy nineteen years of age. But due to the experiments that they endured, Vincent still has the appearance of a man in his twenties, while Shelke physically remains nine years old.
As a young boy, Seere of Drakengard made a pact that bound his spirit with that of his elemental partner. However, like all such pacts in the Drakengard universe, he paid a price over which he had no control. In his case, the price was his ability to age, leaving him trapped in the body of a young boy until the day he dies.
In the universe of Fire Emblem: Path of Radiance and Radiant Dawn, there are beorc, or human characters, and laguz; humanoids with animal characteristics. The laguz have lifespans that extend well beyond that of normal humans, with some races capable of living for many multiple centuries. Should a beorc and a laguz mate, the resultant offspring, referred to as a Branded, retains the appearance of a beorc, but upon reaching a certain age, their aging process slows down dramatically. Micaiah, one of the central protagonists of Fire Emblem: Radiant Dawn, is one such Branded. With her extended lifespan as a descendent of the heron laguz clan, Micaiah spent a great deal of her life constantly on the move, lest the beorc she lived among caught on to her true heritage.