One thing was unrealistic in this movie. Just one.
When Fletcher was chasing the plane on the air stairs, he came up from directly behind the engines on the wings and was able to move forward and past them. Now on Mythbusters, they've shown that the force from one of those engines was enough to roll over a full sized car multiple times from something like 100 feet away.
How are we supposed to buy that?
And let me preemptively answer some of you argumentative souls who don't recognize satire when it slaps them in the face, and who are going to point out the premise of the movie is based on a magic wish: Derp.