when our son got this for christmas i was expecting something bigger when i took it out the box, it doesnt stand very tall and is probbaly more suited to 18 - 24 months and upwards. All the parts need the stickers put on when assembling and the levels kind of stack together. It comes with 5 trains and a boulder. The idea is you let the trains start at the top and then press the button to release the boulder to chase after the train, there are 3 barriers that can be put up and down and on the 2nd level there is a bridge which pops up when the button is pressed and this can be used to stop the boulder from catching the train. There is also a little divider than lets you choose the direction of your train as it reaches the bottom, either in front of or behind the engine shed. There is a turntable at the engine shed so you can choose which bay to park your train in. The trains themselves are diecast and very well made the boulder is made of tough plastic with a face on it. The trains have rollers for wheels which make them glide down the track with ease, after a while our trains became a bit stiff in going down and would stop a lot, it was just a built up or small debris and a quick squirt with polish and a wipe had it as good as new. Our son loves watching the trains race down, he also loves pulling it all apart! but it does go back together easily. We sit ours on top of a storage box and it gives it a better height.