To celebrate the recent launch of Kirby Air Riders on the Switch 2, Nintendo has announced a new event for its Switch Online battle royale game Tetris 99.

This event will take place between 4th December 2025 and 8th December 2025, and allows players to unlock a special design inspired by Masahiro Sakurai's new game. This also happens to mark the 50th Maximus Cup event!

Here are the official details about the theme and the requirements to unlock it:

"To participate, you’ll need to be a Nintendo Switch Online member* and play the Tetris 99 online mode during the event period. You’ll earn event points based on your placement in each match. Once you’ve accumulated a total of 100 event points, a new theme will unlock, featuring art, music and Tetrimino designs inspired by the Kirby Air Riders game that is exclusive to the Nintendo Switch 2 system!"

You can find out more about Kirby Air Riders and Tetris 99 in our reviews. Some of the other Tetris 99 events this year have covered Donkey Kong and Xenoblade Chronicles X: Definitive Edition. In the past, there have also been events based on various other Nintendo franchises such as Mario, Zelda and Animal Crossing.

In some other Switch Online news, Nintendo has released some new Animal Crossing: New Horizons icons for Switch Online members this week. There are also some 'play to unlock' icon rewards based on Metroid II: Return of Samus and Metroid Zero Mission.

Will you be returning to Tetris 99 to participate in this upcoming event? Let us know in the comments.