The most important news leaked before Nintendo Direct was that the new Kirby game would be announced in the presentation because Nintendo was mistakenly listed on the Japanese site. The listing and accompanying image may have been removed from the site shortly, but the surprise was also spoiled.
The game was supposed to be called Discovery of the Stars, but it was announced as Kirby and the Forgotten Land in Direct (japanese; translation didn’t quite succeed).
The biggest innovation of the game is that this Kirby is not a classic 2D sideways platform game, but a completely 3D platform game. The release date is spring 2022.
Kirby and the Forgotten Land will be set in a post-apocalyptic world, filled with what Nintendo says are “abandoned buildings from a past civilization.” So it’s kind of like Kirby meets The Last of Us and Nier Automata:)