I once argued that Happy Feet was the greatest cinematic achievement of all time. However, I came to the realization that using penguins should be considered cheating; their cuteness can only be rivaled by lol-cats. Nevertheless the original Happy Feet remained a fairly entertaining movie with a positive message. The type of film most people want to see when they go to a family film. Happy Feet 2 builds on that and gives it a shinier polish. It is neither better nor worse than the original, just different enough to be an equal and, despite the trailers, not the huge cliché that you are expecting.
There is still a happy ending. But this is a family film called Happy Feet. Anything else would have been a tremendous folly.