Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not sturdy enough for kids

This is very hard to build -- like, multiple adults squinting at the picture on the box and cursing under their breath hard. You seem to have to build what is on the box -- we have not succeeded in varying from the picture much at all -- and even then it tends to lean, tilt, fall over... The whole thing is extremely light weight and unstable (even the "marbles" are tiny, lightweight plastic balls). I would definitely recommend against this marble run. We are back in the market for another one this year, because my kids still want to be able to play with one! We will be looking for one with more flexibility (i.e. it's easy for kids to be creative in how they build it) and sturdier/heavier-weight parts and bases.