Pokemon Rumble World will be made available at retail in North America on April 29, 2016.
Pokemon Rumble World is currently available as a free-to-play game within the NIntendo 3DS eShop, allowing players to enjoy the game for a limited amount of time each day. The retail version of the game will eliminate the need for microtransactions as players will be given a total of 3,000 Poke Diamonds at the start of the game, as well as the Poke Diamond Digger, which rewards you with 40 Poke Diamonds each day you log in, and Pokemon VIP cards. You’ll be given the choice between a Timing Stop VIP Card, which allows you to visit any stage for one Poke Diamond once the Timing Stop opens, or a Balloon VIP Card which allows the use of a hot-air balloon for one Poke Diamond.
The retail version of Pokemon Rumble World will be compatible with the free-to-play version StreetPass and SpotPass, although you won’t be able to transfer your save data from the free-to-play version to use with the retail version.
This seems like quite the oversight as we’re sure many players who may consider picking up the retail version of Pokemon Rumble World may already be actively playing the free-to-play version. Hopefully you aren't too far in your free-to-play version of the game or else buying the retail version could just be a waste of time considering there's no save file transfer.