The Spacerail sets are fairly epic marble runs aimed at older children. It's not like a regular marble run where the marble runs through a chute, instead the marble rolls along two flexible, plastic rails. The track is very intense and gets even more complex depending on the level you choose. The Space Rail Level One is fairly sedate compared to the twists, turns, loops and acrobatics of the Space Rail Level Eight. Infact, many parents suggest that the higher levels are suitable only for teenagers because the instructions and setup is so complex. Even the easier levels will require a certain amount of adult supervision unless your child is particularly adept at construction toys.
The video below shows how exciting the Space Rail can be. Half the fun comes from building the set, which is one of the most challenging marble runs on the market. Infact, for the more complex options
If you think the Space Rail is going to be a bit too much for your child to handle, Quercetti offer a Skyrail option which is similar but not as intense.