"I bought this set for my sons 5th birthday. He loves legos and asked for a train. The train was pretty easy to build. My son did most of it himself with me watching and helping some of the time. The train was a lot bigger than I expected once built. It runs very good, but you have to use all of the track. We tried to make the track a little smaller to put on his train table but the train would only move on the straight track and then stop on the curves because the train is heavy, but once I moved it to the floor and used all of the track it runs perfect. It’s only been built for two days so I’m not sure of the battery life yet. It takes 9 AA batteries."