Earlier this year Nintendo announced that its Dr. Mario puzzle game would return in a new iteration for mobile devices, and now Dr. Mario World has a release date: July 10th. Set to appear on Android and iOS (and available for pre-order via either of those links), it's a free-to-play game with stages where you can either send or receive hearts to other players to exchange extra stamina, or battle online in versus mode.
As one would expect, the goal is to eliminate viruses by aligning them with similarly-colored capsules. The different stages present new challenges, and players have a limited number of capsules. The part that costs money are optional "diamonds" that players can cash in for items, restore stamina or purchase new doctors with special skills instead of waiting for stamina to recover over time or to earn them in gameplay with coins.
Source: Dr. Mario World