It was really only a matter of time, considering the near-ubiquity Animal Crossing: New Horizons has achieved in the mere 11 days since it launched. Smash Bros. Ultimate's Spirit Board is a mode where you battle it out against NPCs to collect various Spirits, some of which appear randomly and periodically for limited-time events.
To be clear, you aren't actually fighting the Animal Crossing spirits, so don't expect to be kicking the crap out of Orville and Wilbur from the island airport. The four Spirits from New Horizon being introduced in the new event are Flick, CJ, Daisy Mae, and Orville & Wilbur (together as one Spirit). You can encounter them, along with every other Animal Crossing Spirit, from Thursday, April 2 to Tuesday, April 7. Check out the full details, including when you can encounter the New Horizons Spirits, here.
Nintendo recently revealed the next fighter coming to Smash Bros. Ultimate will be one of the lanky boxers from Arms. We're not sure which one just yet, but I'm guessing you'll want to keep your distance.
Meanwhile, Animal Crossing: New Horizons just kicked off the eggcentric Bunny Day event, where you collect all sorts of eggs and take on Bunny Day DIY projects. That event runs until April 12, so there's plenty to do in Nintendo land while you wait out the coming days inside.
If you think you've run out of things to do, check out our guide on making your Animal Crossing: New Horizons island tune one of these classic songs.