I work this puzzle with my 3 1/2 year old grandson. In the beginning you can put anything anywhere which he does but he sees how the pieces fit together. As we get to the top we both have to work together to figure out the solution. It takes several tries to rearrange pieces to solve. Grandpa helps but eventually he'll figure it out himself. It's challenging even for adults, It's not that hard but takes a few tries to visualize the solution. I'd say for toddlers it's definitely a cooperative puzzle with an adult's help.

Smaller than I expected about (12" long and 7" wide), but seems sturdy and fun.