Shrek 4-D is like so many other attractions in the area. You enter a theater, put on your 3-D glasses, and watch a movie. Of course your chair bumps, things run under your feet, and you get sprayed with Donkey Snot (puffs of water).
The kids loved it. My wife jumped when the things ran under the chairs.
Biggest problem is that there are so many of these types of attractions now. Honey I Shrunk the Audience, Mickey's Philharmagic, and more. It is getting too much of the same thing.