I really enjoyed the movie. It's funny, the action scenes are very well done, the characters are charming, the dialogues are excellent and the animation style, in a mix of 2D and 3D, is the icing on the cake to complete an (almost) perfect animation.
'Almost' because the plot was pretty average. It's interesting and even brings a nice message, but I think it lacked a little more development, especially in making the movie more unpredictable. Halfway through the movie you already knew who the villain was and how the movie was going to end. They even added multiple 'twists' to make the story more unpredictable, but almost all of them were far-fetched and failed to surprise me.
Despite that, this movie was a breath of originality from Dreamworks after a decade of bland animations. I'll give it a solid 8.