Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not made well enough

In theory, these are great cards. And for the first hour that my little boy used them, they were great. But after the first hour, the cardboard started to give along the points where the pieces join. So, every time my little boy tried to pick one up to show us how well he'd done, the piece would fall out. He became extremely frustrated because he wanted the cards to stay whole, and the pieces simply wouldn't do so. Which caused him to not want to play with the cards, and so made them useless as a learning tool. He had been so excited initially. To see him in tears because the cards wouldn't stay joined was just heartbreaking. I do see that there are wooden ones available through another manufacturer and am going to give those a try. Maybe the wood will stay in shape easier than the cardboard did.