Frozen was just a little bit good and - happily enough - it was also a massive success. It's easily the best thing Disney has made without Pixar's help in years, and makes me feel all warm and fuzzy about the future of animation from the mouse house.And with a gross of more than a billion dollars comes real expectation for a full Frozen sequel. That hasn't been officially announced yet, but with the massively popular merchandise and plenty of rumours of a stage musical on the way, the property is doing a great job of staying in public consciousness. And there's another treat on the way in the form of Frozen Fever.This short reunites the whole main cast of characters from the full feature in a story which is all about trying to prepare a very cool birthday for Anna. But when Elsa gets a bit of a sniffle, things get complicated and - I'm assuming - a bit slapstick too. Here's the trailer.