Happy Feet is a movie I probably would have enjoyed much more when I were younger, when I still believed that something like the happy ending of the movie could have really happened (I actually like happy endings, but a movie that tries to aim for a serious theme, I expect them to go through with it all the way). Now the ending leaves a bitter taste, reminding me of all the animals that have gone and will go extinct thanks to us humans. Compared to reality, the ending of Happy Feet looks either like a really bad joke, or plain wish fulfillment.
The movie itself has far too much music for my taste. Despite it being an integral part of the plot, it soon became annoying. Another problem are the characters themselves. There’s a reason why other animated pictures with anthropomorphized animals have many different kinds of them as characters. If you have too many of the same, they all look alike. I really had a problem to distinguish between most characters in the first half of the movie.
Also the plot of the movie seemed a bit unfocused. First it’s an ugly duck plot, then it’s about tradition vs something novel, and the last part of the movie is about finding the aliens (us humans) and help the penguins to survive. The inclusion of the environmental message was far from being subtle, but like I already said, worse was the happy ending. If you want an environmental message, a reference to reality, let the penguins starve to death and the main character rot in the zoo.