Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Poorly designed toy

My 3 1/2 yr old son LOVES Thomas and Friends. He was thrilled when he received Thumper because the Boulder video is one of his favorites. Unfortunately, I agree with the other review, the tread constantly comes off Thumper. As soon as my son pushes Thumper the tread slips off and I have to put it back on. This is extremely frustrating for anybody much less, a toddler. He went from being thrilled to chilled. He occasionally comes back to Thumper and tries to play with him, but of course, the tread slips off and he is disappointed. This is definitely not a well designed toy when it comes to the treads and their fit. The rest of Thumper is just as cute and durable as all of the other wooden Thomas trains. Skip buying this one if you can, otherwise your child and you are in for frustration and disappointment.