I went last night on our last night of our trip. The store closed at 11 pm. They text you when it is your turn to play. I had 15 minutes to return in order to get in line to play. You can text them back if you are running late or change your mind.
I hung out in the store while the rest of my family went to the christmas tree trail (we didnt have time to do both and my Wife insisted since I have been waiting forever for this game lol). They have 2 big TVs showcasing gameplay and trailers while you wait. They have some photo ops and some keyblades to see. The only merchandise you can buy is preordering the game itself. There isn't much to do other than play the game.
Once called for your turn, you are assigned a number and wait in line. You will then go to your assigned console to play. You have 15 minutes to play. They have 2 levels: Toy story and Olympus. I chose Toy Story to do first, beat it then made it pretty far into Olympus before my time was up.
One tip: Skip the cutscenes! You will lose 7 minutes of playtime if you watch them all (I asked).
Definitely worth it! It was packed when I went on Thursday night. Have fun!!