1) Mine.craft is a form of escapism- the game contains a world you can completely explore and build on your own. If you ever want to get away from the world or your problems, you can go to your own world.
2) The game can be played together. Mine.craft is a game you can play with friends, and also online. It's always fun to play together with friends.
3) Mine.craft is a game you can fully customize in the way you want it to be. You can decide how difficult you want the game to be, if you want play alone or together, if you want to fight monsters, if you want to find everything before getting to build with it or if you want to have everything you need, right when starting. The posibilities are endless.