Pixel art seems to be easy peasy, since the details are simplified. In truth, the limitation in size is what it makes it much more complicated than regular illustration/animation. You really need to use your wits to be able to stuff as much detail as you can in just a few number of pixels and still be visually adequate and expressive (e.g. the distinctive quality and motion of hair of each character).

I was hired by a small game developer team to help create the sprite sheets of their 2D rpg game called Erah. The payment was rather symbolic, but it was a fun project so I didn't mind that at all. Especially, because I was completely new to this type of art.