I simply love this game. It has to be the most simplistic and successful game made, besides well, Pac-man or something. Other than that, it's an awesome game. I find you can do tons of things in it, whether it would be hunting, farming, building something, exploring caverns, or even just mining. I find that I can spend days (with sleeping of course) playing this game. With the new 1.4 update, it's even better. I have yet to try out the update myself, since I am too busy having fun on multiplayer.
To sum it up, Minecraft is a great game if you have autism, or something. I recommend you play it, as would millions of others.