Download Play is a feature first introduced on the Nintendo DS that allows units to share one Game Card for multiplayer gameplay, or send and receive game demos. Download Play has since then been included in all the forthcoming Nintendo DS models (Nintendo DS Lite, Nintendo DSi, and Nintendo DSi XL) as well as on the Nintendo 3DS, Nintendo 3DS XL, Nintendo 2DS, New Nintendo 3DS, New Nintendo 3DS XL, and New Nintendo 2DS XL.
Download Play on Nintendo DS
DS Download Play is located within every Nintendo DS model which allows players to use Download Play. The host (the player with a Game Card that allows DS Download Play to be used) will create a lobby and other players will join by pressing the DS Download Play icon on their system's menu. Once the players have been confirmed by the host, the lobby will be closed and the game will begin downloading onto the other player's systems. Once the host powers off their Nintendo DS or ends the game session, the other players will then be forced to turn off their systems as well or go to the system's menu. Due to limitations in the system's hardware, the game cannot be saved onto the system nor does gameplay during Download Play allow all features of the game to be accessible. Some games that allow Download Play include Mario Kart DS, Metroid Prime Hunters, and The Legend of Zelda: Phantom Hourglass.
Using the Wii's Nintendo Channel, owners of Nintendo DS can download demos of retail games. In this case, no Game Cards are involved and the Wii will serve as the host. Demos are also available in select retail stores.
Download Play on Nintendo 3DS
Nintendo 3DS systems utilize Download Play in a similar manner as the Nintendo DS. The only difference is that Nintendo 3DS owners can play Nintendo 3DS games as well as Nintendo DS games. Upon launching the Download Play application from the HOME Menu, players will be asked to choose whether they will be downloading a Nintendo DS game or a Nintendo 3DS game. If Nintendo DS is selected, DS Download Play will be launched (for compatibility reasons). If Nintendo 3DS is selected, the system will begin searching for a game. Unlike DS Download Play, if 3DS is selected, if it does not find a game, then it will stop searching, and ask the player if they want to search again, while DS Download Play would search until it either found a game, or the player exited.