ThinkPlay STEM are great for getting your kiddos excited about building. I love that they come with a book in different things you can make but you also have the choice to get super creative and build whatever you can imagine. It comes with a bunch of different block pieces in different colors. They can be stacked or stuck together by sliding the pieces into each other. Our daughter can’t slide them together yet but she’s getting close. I even think they are hard to put together and take apart. So when we use these I start the pieces but let her slide them all the way. It would be better if they snapped together. What is great is the sense of accomplishment and pride she gets from completing a project.