The latest essay on Henry Jenkins' blog, is an excerpt from a thesis by Kristina Drzaic, about "secrets" in Animal Crossing. The idea is that other games feature glitches that allow the player to redesign the game in small ways and alter the basic experience, whereas Animal Crossing features such "glitch-like" abilities as part of the natural design of the game, and allows even more customization than the engine was designed for. One example showed a player creating a narrative conflict between herself and Tom Nook just by trying and failing to buy some candy.
We were just wondering aloud why customizable content was so compelling! Good thing there are people smarter than us out there.