In Animal Crossing you play a little human who lives in a small village with a bunch of animals. The game does not have a linear narrative structure, except that it is tied to the Gamecube’s system clock. So when it is night in the real world, it is also night in Animal Crossing. The same is true for the seasons and certain holidays.
The whole game revolves around talking to the animals through simple multiple choice menus, doing jobs for them, sending letters, collecting things and decorating your house. You are awarded points and money for certain things, but it’s the ambient sandbox experience that really drives the game.
On the surface there doesn’t seem to be much Artificial Intelligence in Animal Crossing. A lot of things indeed seem to happen at random. But the game is very succesful at displaying credible characters for which you can feel real empathy.
The animals in the village are capable of remembering you and developing a simple relationship with you. Some characters are easy to become friends with and others have a more difficult personality. It seems like there are only 5 or 6 different personalities. So there’s always multiple characters with the same personality.
The animals also have relationships with each other. They talk to each other (though you don’t know what they say) and as a result they can get happy or sad or angry. If they really like each other, they will change their outfit to be the same as the other critter and they will hang out in the same area often. Until they break up.
Animal Crossing is of course a good example of how one can make simple A.I. seem convincing if the characters are animals, and very cartoony ones at that. The designers really exploited that element, but I still think there’s things to learn from the game for more realistic applications.
The animals have very simple ways of expressing themselves. But these are very efficient. When they are annoyed, grey clouds appear over their heads, when they’re sad, rain falls out of those clouds. When they are happy, they radiate flowers and when they are in a good mood they walk around whistling.
I have only discovered some 15 emotions that they can express and still the characters are credible and endearing. You can’t hep but feel sorry if one of them passes by with a raining cloud over his head.