While looking for ways to activate the developer menus left over in Animal Crossing, including the NES emulator game selection menu, I found an interesting feature that exists in the original game that was always active, but never used by Nintendo. In addition to the NES/Famicom games that can be obtained in-game, it was possible to load new NES games from the memory card. I was also able to find a way to exploit this ROM loader to patch custom code and data into the game, allowing for code execution via the memory card.

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