Captain Toad first debuted in Super Mario Galaxy and then became the star of his own set of minigames in Super Mario 3D World. Nintendo thought those were a good enough idea that they made them into their own full-fledged game, Captain Toad: Treasure Tracker.
In Treasure Tracker, you take on the role of both Captain Toad and Toadette, each having to save one another as they track down the villain, a crow named Wingo. Along the way, there is of course treasure to track down and secrets to find.
Each level is its own scene taking place in an interesting location, ranging from a volcano, to a haunted house, to even New Donk City. Captain Toad is giving Mario a run for his money in places he's visited.
Captain Toad: Treasure Tracker even features local co-op, where a friend can join in as their own Toad to figure out the puzzles with you.