Disney still owns Mickey Mouse the character. They have his name trademarked and that will never expire. The copyright to Steamboat Willie is what they lost, and thus people can now use the content of that short to their heart's content, so long as they don't actually use the name "Mickey Mouse" proper.Someone's going to have to explain to me why Disney no longer owns Mickey but Warner Bros. still owns Bugs and Porky. Does Steamboat Willie's status as his very first cartoon have something specific to do with it?
Nonsense. It's making new content of a horrific monster that just so happens to look a lot like the Steamboat Willie version of Mickey Mouse, but isn't actually considered the same entity as Mickey Mouse from a legal standpoint because it isn't actually named "Mickey Mouse" and doesn't take inspiration from the traditional, red-pantsed, falsetto-voiced, official version of Mickey Mouse that Disney does still own and can still fight to protect the copyright of. Therein lie the legal loopholes that this game is taking full advantage of.But that's literally what this game is doing, making new content of Mickey Mouse.