I have two kids, a son 5 and a daughter 8 who spend a lot lot of their free time on Minecraft(pocket edition on Kindle Fires). I'm kind of amazed at the kind of stuff they come up with. My daughter mostly uses for "artwork" building sculptures and statues and things like that, basically an extension of the drawing she does when she's not on her Kindle. That was basically my expectation when I got Minecraft for them as I was familiar with the "virtual lego" aspect of it, but my son has really surprised me. He uses pressure plates, switches, dynamite, red stone, etc to build all these little machines(my daughter does too, but not to the same extent). Looking closely at what he builds I didn't expect my 5 year old to have the kind of grasp on programming-like logic.

I had originally set up a Raspberry Pi to hopefully teach him some beginning programming(my daughter has a Chromebook with regular Linux installed, and I've taught her some Python and HTML) with Scratch, but he had not interest in it at all, but he did find Minecraft on the Pi and for the first few days both kids where gathered around it until I put in on their Kindles to give them a newer version and one where they can play together.