The differant graphics of a videogame can shortly depend on the style the directors of the game want to have the game look like and be known for. The style of any video game is very important and based on what graphics would best suit that story.
Photo Realism in gaming are those few games that try to reach out to look like its actually there, that the game is real, that a photo has just been taken. One game for the wii that is photo realistic is, The Legend of Zelda: Twilight Princess. This game commonly has human characteristics and facial structures, plus the surrounding areas of this wii game contain a realistic emphasis on things such as the; mountains, lakes, forests and towns. Some more photo realistic games include; Heavy Rain for the PS3, Gran Turismo 4 for the PS2, Monster Hunter Tri for the wii and Resident Evil for most consoles.
Exagerated Games are often found in Japanese games, One that appeals to many is the puzzle/ story like series of, Proffesor Layton. Many characters in the Proffesor Layton series will commonly have a larger nose or larger eyes, or even an exegerated size and shape of their heads. Other games that appear exagerated are; The Final Fantasy series, Tales of symphonia and The Dragon Quest Series. Nearly every exaggerated game has everyone with big eyes.
Cartoony games often look to realism, with the addition of bright colours and exagerated shapes to make characters into a cartoony, sort of story world, almost like a story book. Super Mario Galaxy, is a game that use the cartoony sought of look and style, in actual fact, wherever Mario is dipicted, he always looks like a cartoony style of character, as this style just suits the Mario games alot more than any realism would do. Some other games that have a cartoony touch to them would be; Avatar the Last Airbender ds series, the Sonic series and even Wind Waker has that cartoony feel to it. Cartoony games are always good for adventuring games or games that simply dont need any realism because they're story is just that much so gripping, that graphics dont matter.