A few weeks back, my 8 year old nephew came to my home. He always runs directly to my room to see if I have any new games to play, and I did have one. I always struggled to show some of my hottest games to him, because he's younger and I feel pretty unconfortable showing him M rated games, I even gave him a copy I made of my original disk of Crysis. And also he gets bored of watching me play a regular MMO and he easily gets very frustrated if I let him play Super Meat Boy.
But last time he came, I showed him Minecraft and he left completely fascinated by it. We spent the whole noon playing together, the game was pretty inofesive (and terrifying) for him and we both enjoyed it immensely. When I showed him the game, I started a new world, showing him the mechanics and why was it necessary to survive the night. He even loved the graphics, to him, the game didn't looked pixelated as I may call them, they were just "blocky" for him and he always marvelled at strange "natural" formations that the game randomly generated.
It's a bit sad that the game in it's actual beta status won't give the full access to the entire game as if I bought it from alpha (wich I did), because if I knew before that he would like it so much, I'd gladly buy the game for him. I found the perfect "Lego" for him.