The setup in Amity Square is identical to the Pikachu interaction system that was in Pokémon Yellow. Only certain small Pokémon can be taken for walks in Amity Square, usually of a "cute" appearance. Pokémon will fetch Accessories or Berries for their owners every 200 steps.
In Pokémon Platinum, more Pokémon are allowed in than before, and the area has been expanded and redesigned. It now includes a rather large pool of water on the west side, with a model of the Sinnoh region within. Rather than being able to cross the entire square as in Pokémon Diamond and Pearl, it has been separated into exclusive east and west sides, each only accessible via their respective gate. Of special note, Pokémon Platinum allows all three of the Sinnoh starter Pokémon and their entire evolution families.
The rock huts serve no purpose in Pokémon Diamond and Pearl; however, in Pokémon Platinum, they contain warp points that send the player to another rock hut in the park. Each hut contains three warp points, accessed by walking to the front, left, or right while inside the hut.
After taking an allowable Pokémon for a walk, players will find that their party has been fully healed.
In Pokémon Platinum, a man who, once a day, will give the player five of a Berry or one Accessory appears in the eastern side of the park. When the player enters the Square, the man will be in one of the isolated locations only accessible through the teleporters in the huts (the teleporter on the north side of a hut will always lead to one of the huts connected to the park's entrance/exit).
So long as the player stays within the park, the man will always offer the same item, but if the player has not accepted an item from the man, he may change the item he offers (as well as his position) if the player exits and reenters the park (such that the scene changes).
This section is incomplete. Please feel free to edit this section to add missing information and complete it. Reason: Add Accessory rarities for Platinum. Add Shroomish, Skitty, Torchic, Jigglypuff for Diamond and Pearl.
Every 200 steps, the player's Pokémon will pick up an Accessory or a Berry. The Accessories the Pokémon may pick up differ depending on the Pokémon. The player can have up to nine of each Accessory; if they already have the maximum amount for an Accessory, their Pokémon will not pick up more of that Accessory (eventually leading to a situation where the Pokémon picks up only Berries if all Accessories are at full capacity).
While Amity Square hasn't directly appeared in the Pokémon Adventures manga, it was mentioned by Cynthia in Suffering Psyduck. She told Diamond and Pearl of an incident where a person had been walking with their Psyduck in Amity Square when it suddenly disappeared. She also remarked how a large group of Psyduck had soon after appeared on Route 210, blocking the path to Celestic Town, and suspected that these two incidents were connected. She also revealed that Mr. Backlot is the owner of Amity Square.
The northern section of Amity Square draws inspiration from Cappadocia, where houses have been carved from hoodoos.
It is revealed by a citizen of Hearthome City that Mr. Backlot, owner of the Pokémon Mansion, owns Amity Square. The women at the gates of his mansion say that the owner can be found in somewhere on the grounds, but this is false as he is always inside the mansion.
If the "walk through walls" cheat code is used, the game will pre-select the first Pokémon in the party, which will be taken into the garden with the player; however, it will not be able to be seen or be able to pick up items. The player only notices the Pokémon's presence when speaking to the receptionists of either entrance.