"Build this together with my 2,5 yo. It was a challenging build for him, but the set made it easy with a clear difference between one piece and the next (either in color, or shape). The build itself is also very sturdy, (except for the tree), the firecar holds up to a lot of a abuse.
It's also great that the wheels go on first! We've had lots of adventures with it and he loves to take it apart and rebuild it together. We've had the set for about 8 months now and he mostly knows it by heart now.
I've bought an extra copy to store for when he gets older, because I think this is his "first" LEGO set.
We have bought some other 4+ sets since, but this one stands out in building experience and sturdiness."