A general overview of the ride....
You move through a couple of "holding chambers" that have either a tv show or a robot that it telling part of the story. You are being trained to be a part of the team that handles dangerous inmates (i.e. its a jail) so there is a little story to it. If you have seen the movie, you will recognize the final chamber where Stitch is transported into the center glass cell and of course escapes and creates all kinds of havoc, like eating through the electrical cords, burping and spitting, jumping around the room, and getting into all sorts of trouble. The guns are active - trying to fire at him some and he has to disarm them as well (the DNA weapons from the Stitch movie). When he kills the power, it is dark in the theater for about 20 seconds. The seat back that lowers over your shoulders is to allow stitch to "jump" on you and it has all the sounds and smells and water in it. Basically, it is a 4-D show with Stitch.
My 2 and 4 year old think it is a fantastic show! They are looking forward to riding it again as both love Stitch and all his antics. I simply reached out and held their hands beside me when it got dark in the theater. No problems at all.
I think it is a cute ride and we will ride it often. I never did Alien Encounter, but it is my understand that this is a more friendly version of a similar ride.
Try it! It seems to be one of those you have to try to see if you will like it.