One of the new features in Kirby: Star Allies is the ability to befriend enemies. These include classics like Meta Knight and King DeDeDe and other iconic enemies, such as Waddle Dee and Bandana.
On March 28 there will be an update that will allow you to befriend Rock, Coo, Marx, Gooey and Kine.
Also, for those still on the fence, there is a downloadable demo of Kirby: Star Allies on the Nintendo eShop and on display at retail demo stations.