My 3 1/2 yo boy is into superheros and superpowers and he likes to pick different combinations and fight them and after fighting enough we'd become friends and continue by fighting bad guys. And each time he plays he is just as enthusiastic as previously.
From a grown up point of view it is a waste of time, but I'm sure that for a kid it means everything and the catchphrase on the first ad manages to point this thing out: "For a kid a toy is NEVER just a toy"
My son is also 3 1/2 yo and seems to be all over the place. He's pretty good at the computer and he can switch login identities,knows the few symbols to get to his mickey mouse games and can play some games very well. He just picked it up real easy. I stopped playing guitar 3 years ago so I could spend time with him. Reading to him puts him to sleep if he'll sit and listen to me