Captain Toad: Treasure Tracker was previously a Wii U exclusive but will release on Switch and 3DS next month with new content!
On July 13, Switch owners will not only get two player co-op, but also brand new levels from Super Mario Odyssey which replace the previous Super Mario 3D World levels found on Wii U.
Whether those Wii U levels appear as DLC at a later point is unclear, but for now, Super Bell Hill, Conkdor Canyon, Shadow-Play Alley, and Clear Pipe Cruise have been removed from the game.
A demo is available for Captain Toad: Treasure Tracker on Switch which enables you to check out the co-op play before the game releases. The demo features two of the early levels as well as the first boss in the game. The levels are Plucky Pass Beginnings, Mushroom Mesa, and The King of Pyropuff Peak.