I wouldn't classify this as a typical bad movie. It has great production values and a great cast of talented actors. However, the unintentional funny lies within the story telling. It is very emotional overall and the movie is build on these factors: happy and sad/dramatic.
When they are happy they are on crack. It's over-the-top frolicking with running, dancing, shouting, spinning and laughing.
When they are being sad/dramatic you pretty much get the same except they are not smiling. They run, they shout, they roll on the ground, they stare and they cry.
First thing I noticed is there doesn't seem to be any middle ground. They cut directly from a happy scene to a sad/dramatic scene and so on. It's like a 12 hours mini series edited to two hours displaying emotional highlights.
Other than that you get Robert de Niro as the philosophizing creature body slamming villagers or wrestling nude with a bare chested Kenneth Branagh while both are soaking wet. Be warned indeed
Worth checking out.