The frame is a little awkward and the narrator feels a little obtrusive, but on the whole this is an excellent time travel story. I liked it a lot. If I was younger I might have loved it. Much of the information about the Children's Crusade was exciting and interesting, I think its a great choice for the incident in history that the main character time travels to. I also really liked that he wanted to go so he could see knights in armor and tournaments and he ended up spending most of his time with children and ordinary working people. Nice touch.
I guess I'm not giving it more stars because some of the time the places and people felt a little generic. They stopped in a village, or a town, but there was nothing to make that village or town much different from any other village or town. Some of the characters kind of felt like extras or spear carriers in an opera - sort of interchangeable. I guess I could have done with a little more vividness in the settings and characterizations. Still, a very good book, and recommended. I'm glad I read it.