Koko-di Koko-da isn't the first film to use horror as a metaphor for personal drama/illness, but it's certainly one of the most original ones to do so. While director Nyholm doesn't quite nail the balance between horror and drama, but there are so many memorable moments that it hardly matters.
On a trip to celebrate Maja's birthday, Elin (rather brutally) discovers she's allergic to shellfish. She can laugh it off, but after spending the night in the hospital with her family, their trip becomes even worse. When they awake, Maja has died. Three years later, Erin and her husband go on a camping trip that will force them to face the demons haunting them.
It's pretty much impossible to categorize Koko-di Koko-da. Not only does it cycle/combine several genres (mystery, horror, drama, comedy, fantasy), it also doesn't stick to conventional genre structures. There are surreal characters, beautifully animated scenes, some very crude and dark horror moments and more things I'd prefer not to spoil. If Nyholm could manage to bring everything together without it becoming too heavy-handed, I'm sure he can deliver a true masterpiece. He sure got close with this film.