My five year old really enjoyed this set. As a mom, I love that it provided a screen-free activity that required him to sit down, focus, and follow directions on his own without help. As a teacher, I appreciate the huge variety of skills Lego sets help develop like executive functioning skills (attention, focus, planning), spatial reasoning (a strong predictor for future math success), perseverance, problem-solving, STEM concepts (stability, gears, balance, etc.), fine motor development, etc. I also appreciate that they are tiny and don't take up much space. I can store them in a bag with the directions and my boys can rebuild them later or I can just toss the pieces in with our thousands of other Legos and they can use them to build something completely new (either from their imagination or something generated using the Lego app).