The retail release for Tetris 99 will come with a year's worth of Nintendo Switch Online.
Tetris 99 is getting a retail release which includes the paid-DLC and a one year subscription to Nintendo Switch Online.
The Big Block DLC is available to purchase from Nintendo eShop for $9.99. At present, it comes with CPU Battle and Marathon.
Further offline modes will be released this year as part of the package, one of which is eight-player local multiplayer. More information will be revealed on the content at a later date.
Nintendo Switch Online runs $19.99 per year, so you're basically just buying the DLC with a subscription and getting the game free - which Tetris 99 is free for Switch Online users anyway (thanks, Polygon).
Tetris 99 will be released at retail on September 6 for $29.99.