This is fun and a great way to teach kids about a number of things, mostly how to follow directions. Some parts are plastic and will break, it's easy to make it wabble, but it's Fun! The key is to make some minor adjustments as you go along. Ball speed can make a big difference on the track. I have put two tracks together already. Now I'm going to put the two tracks together. Also, just FYI, the level 9 needs to be modified to a degree. It is fun getting it to work as intended.