My son of 4 had a blast building this set. It took him some time, but he managed to build most of the set without much help. A lot of build and play fun in one box. He really likes the moving launchpad arms and the little train of this set.
But a big design flaw in this set are the rocket booster caps! They pop off very easily! One is also a little skewed :-(
Rocket is super solid, but the booster caps reduce the playability a lot!