New Super Mario Bros. Wii Coin World
From the Super Mario Wiki
The gameplay features multiplayer, much like its console counterpart, and is based primarily on a slot machine mechanic. The game features a variety of "event" elements as well, each based upon gameplay from New Super Mario Bros. Wii. Winning various events and on the slot machine gives players opportunities to collect keys. Once 5 keys are collected, the player enters an event with Bowser to win a jackpot.