Dobutsu no Mori+
December 14, 2001
In Dobutsu no Mori+ and its revisions (Animal Crossing and Dobutsu no Mori e+), the complete Famicom/NES game Baseball is featured as a playable mini-game, though it's only obtainable on "the Island", accessed by connecting the Game Boy Advance to the GameCube.
See here for other NES games included in the game.
WarioWare: Smooth Moves
December 02, 2006
One of 9-Volt & 18-Volt's microgames is based on Animal Crossing: Wild World. Starting with the "Remote Control" form, the player pull the Wii Remote at the right time to catch the fish.
Despite being mainly based on Wild World, the background music is "12 PM" from the original Animal Crossing, and also the presence of lilies in the pond is based on that game.
July 27, 2018
This game is a compilation of microgames from the entire series, and one of 18-Volt's microgames is the "Animal Crossing: Wild World" microgame from WarioWare: Smooth Moves, which returns with the graphics slightly altered. Also the background music is now the "3 PM" theme from Animal Crossing: Wild World and Animal Crossing: City Folk. Being part of the "Twist League", the microgame is now controlled by tilting the console.
The game also features compatibility with many different amiibo. Scanning a compatible one will make Wario draw a sketch of the character, which can be exchanged for in-game coins.
This includes all the Animal Crossing amiibo, though both Isabelle variations will produce the same sketch; also amiibo cards are not compatible.
Sketches made from Animal Crossing amiibo are: (Note that while the main subject is always the same, the background and the style of the painting are randomized each time)
Copyrights for both series are held by Nintendo.