As someone in my thirties who enjoys DIY, I found it pretty challenging, so I definitely wouldn’t recommend this for kids or teens.
I built it with my 6 years old son. It's took us 4 days, 2 hours each. The instructions are very clear with all the details. Even my son follows and understood instructions very easily. The end product is very pretty especially when the light turns on. The only part I find difficult is removing the S, L, and M stickes, since they very tiny. I then used a tweezer to remove them and place it on the material. My son enjoyed building it and loved the final product. Highly recommend it to every one and especially to parents with kids.