I just saw that the new Lion King is 2 hours long, which is way too long for my son in the theater. Toy Story 4 couldn't hold his interest, which is an hour and 40 minutes. I appreciate you saying some parts might be scary for a 4 year old. It is so difficult to predict what will scare kids. They won't be bothered by something you would have bet on scaring them, and something that doesn't seem scary at all will terrify them.