The Sony Pictures Imageworks animators studied human skin and coloration in developing the textual quality of Smurf skin, so the Smurfs would not seem "alien" in a live-action setting.
In the restaurant, Gargamel throws a plate with bread up in the air with Azrael, it falls and a breaking sound is heard. However, seconds later, the plate and the bread are on the same place as if untouched.
When Clumsy runs to the waterfall, Grouchy says that they are down to 99 smurfs, implying that there are 100 smurfs in total. In fact, counting Papa, there are 101 smurfs.
Narrator Smurf: There is a place. A place that knows no sadness, where even feeling blue is a happy thing. A place inhabited by little blue beings three apples high. It lies deep within an enchanted forest, hidden away beyond the medieval village. Most people believe this place is made up, only to be found in books or children's imagination. Well, we beg to differ.
Gargamel: [playing with puppets]
La la lala lala, sing a happy song! La la lala lala, this is so wrong! "Oh, I'm Papa Smurf. I'm the head of a small group of blue people, and live in the forest with 99 sons and one daughter! Nothing weird about that, no no, totally normal!" "And I'm Smurfette! And I think I'm so pretty! And I betrayed Gargamel, and I don't even care! And everything is just sunshine and rainbows!"... But all of that is about to change!