Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Love the Tube Trax

My wife just found one of these sets, and I've been helping my 4 year old son build it. The pieces are sometimes a little finicky, but it's worked very well. I wonder if people finding it "impossible" might have gotten a second-hand set with pieces that were meant for other toys. It's a great concept and good fun.