My 3 yr old loves this. Plays ALL the time with it & it has put up with some heavy playing from a very 'lively child'. It does come with lots of bits, but he can put it together and apart with ease. They are easy for 3 yr old to put together/apart!!!
Only bit he needs help with is the lift (which if you put together, suggest you leave together as does get weaker if keep taking apart), but once we put that together - no stopping him again. We have had this in so many different ways it's untrue. You do need to leave the top off the office for the voices to work properly, but this is after ALOT of play. It worked perfectly at first, but it has had some hammer!