Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Flimsy

Bought this for my daughter a couple of years ago. She has fun with it, but is always very frustrated with how flimsy and unstable the structure is. The motorized part does not always pick up the marbles and it is very hard to find replacement parts if pieces break or go missing. Overall, not good value for money. The wooden marble structures look far more stable.