Dr. Mario World is an upcoming mobile title being developed by Nintendo in collaboration with Line, and NHN Entertainment. The latter of those has some experience with mobile games and the market surrounding them, having released RWBY: Amity Arena and Crusaders Quest on mobile, as well as several other titles.
The game will be a spiritual sequel to the original Dr. Mario which came out for the NES all the way back in 1990. The new mobile outing follows a variety of sequels to the original over the years. Nintendo has previously created Dr. Mario 64 for Nintendo 64, Dr. Luigi for Wii U, and Dr. Mario: Miracle Cure for Nintendo 3DS.
As for gameplay, we know that the game will be some type of action puzzler in the vein of the original game. Although we’ll likely see special items being used to overcome challenging boards, which will probably be key to the monetization strategy, as well as leaderboards for player rankings. The development team could also implement a bunch of rankings for individual boards, as well as a general competitive mode so players can find out who the best really is.
Dr. Mario World is due to launch as a free-to-play mobile title in more than 60 countries, and of course it will have microtransactions. The game will be out in Summer 2019 for iOS and Android.