|Laser King T-Reximus|
Minecraft breaks down into two modes: (with very similar core game play mechanics) survival and creative. Survival is simple; you build during the day and you survive during the night. Creative (it's much simpler) gives you unlimited blocks and you can't die (for uninterrupted creativity). The game itself breaks down into mining and crafting. You mine and get enough stone to build a castle (or lava barfing dinosaurs). Then you build that castle (or aforementioned dinosaur), and love every minute of it.
With Minecraft's charming art style and easy pick up and go game play you get hooked fast and hard (you really are only limited by what you can think of). On top of all that, this game is stupid affordable (Just about 12 bucks). If you hit up Minecraft.net you can play "Classic" for free and get a feel for the game. Give the free version a shot and join the rest of us!