I bought my son a year thinking that a box shape would be ideal to stimulate. But the toy itself is too complex for him. He loves the lid to drop a bunch of objects. The keys are easy to carry, ideal for noise and suck. That's why I chose. A keyring for small it is always interesting. He understood that we could put the forms by the cover and the animals in the doors but it's not very functional. The keys are too hard and the inclination of the roof and doors require too much adjustment for small hands not very clever. What he likes most is to see her brother 3 years to do it and explain it! No worries for keys and even less for the different forms. Great to learn or review the colors and names of objects. I just wonder how long the roof will resist dismantling the many he endures?