Minecraft is a first-person fighter/sandbox construction game created by Mojang AB.
Not a bad game. The dev of it though seems to think it's almost finished.. IMO, it's far from it.
Minecraft (Single Player) as is, is pretty much:
1) Gather resources.
2) Build / Craft with those resources.
3) Go to 1.
Why can't there be some seed generated towns, npc's, dungeons and quests too?
The game really isn't optimized well either. You'll probably have better luck running Crysis than Minecraft.
Minecraft is truly a great game. It is both challenging and fun to play. The huge amounts of freedom to do whatever you want has never been seen in any other game.
The problem is that "to do whatever you want" doesn't involve much choice. The gameplay itself is quite shallow, and the play usually doesn't have much to do except, well, mine and build stuff. After a while, even the fighting starts to feel like nothing but a minor disturbance.
The lack of a large variety of blocks to spread across this huge world, and a purpose to keep moving on and playing this game simply ruins it.
Maybe some NPC's, quests, goals and challenges will make this game a true masterpiece. Until then, it's a 6/10.