Directly to you from Twitter:
A free demo for #Kirby Battle Royale is now available on Nintendo eShop for #3DS. Transfer Meta Knight and coins from the demo to the full version when it's released on January 19th! https://t.co/AL30tSbCqx pic.twitter.com/P79QxCfacX— Nintendo of America (@NintendoAmerica) January 4, 2018
…Wanna play? Buy a 3DS.
And if you’ve already got yours, click on Kirby Battle Royale for everything you need to know about the game. 😀