gravitrax starter set
The gravitrax starter set is a nice pieve of modern 3d-puzzle work. It's certainly nice to play with if you like marbles.
But it's also a rather limited set. A marble runs through the setup in give or take 5 seconds. So while you have fun building the track, the fun for playing with it is over soon.
Maybe the biggest miss of all is the size of the marble. due it's small size it's not possible to play with the set if you have small(er) children.