Minecraft is an open world indie game first created around 2009, with many updated versions having been released since. The game was developed by only a few main people, one being Markus Persson, also known as Notch, along with Jens Bergensten, Daniel Rosenfeld, and Kristoffer Zetterstrand. However, it is currently being handled by entire companies, particularly Mojang AB.
Oh, Minecraft... Minecraft, Minecraft, Minecraft.
There is just something about this game that keeps me at it for so long in the way that there is infinite possibility, a simple gameplay mechanic, and no one around except for me, the surrounding creatures, and potentially anyone I want to hang out with.
In this way, Minecraft is just great to play if you want to escape. It's an opportunity to stop thinking about all the people you know and what's expected of you, and to just explore this bizarre universe, build your ideal home, just find something extraordinary, or even conquer the terrible Nether.
Whether you want to cover half the world with your castle or just build a small fort and otherwise fight off hordes of evil creatures, you can do it all in the world of Minecraft. In a word, it's just endless.
As of now, I don't have tons of experience with Minecraft. I've just built up a relatively small castle-like fortress with a wooden roof and some of the basic utilities. Yet, I have big plans for a castle in the sky, and I'm placed conveniently next to a huge cave system (seriously, it's right in my front yard), so that is some huge exploration and resource potential. In fact, I have a funny story about that cave:
I just stumbled upon the main entrance on my first or second day playing, and I'd made a huge ton of torches, so I figured it would be a small little place I could map out. Yet, I kept going along and there were a bunch of waterfalls and crossroads and dark caverns, to the point where I not only had barely any torches left, but had no idea where I was. I made an attempt to backtrack to no avail, and I was put on edge by the fact that there was thunder and rain audible outside.
However, I managed to escape the situation with some brilliant Minecraft logic. See, in this world, everything is on an even plain because everything is a block, and because literally everything is destructible, I just went with the simplest idea there was: Dig UP! So that's what I did. And after not that long a time, I made my way out through a cave entrance that was in back of a hill right next to my fort! Wow. All that on the first or second day, huh? That's Minecraft for you, I suppose.
The cool thing though, as I said before, is that you can do just about anything in Minecraft. You can constantly go spelunking and try to find a load of every ore, or you can grow wheat and sugarcane, breed animals for experience, and tame dogs or cats for companionship. I personally do both. A lot. Although I still need a better house.
The point is, I can hardly think of any negative thing at all that can be said about this game. It's your own world to live in, but it's your own land where you're the sole hero, and you can paint the canvas of the land however you please.
Not only that, but the game is ever-growing, and is constantly being expanded and updated by the good people at Mojang. They add everything from new foods, to new blocks, to new gameplay mechanics, and even entirely new biomes, usually on a month-to-month basis. This increases the game's replayability almost perpetually as you explore and have fun with each new addition to the Minecraft universe.
I can think of no open-world game as inviting or as wonderfully simple as Minecraft. If I had to come up with one complaint, it would be that some slight lag is possible on smaller computers, but otherwise, it is completely worth any effort put into getting it, so I suggest you download it now. It's only a little under $30 for the PC version (which can be downloaded with a prepaid card or by PayPal), and it's also available on the Xbox Live Arcade for 1600 Points, which is well worth it for such an extraordinary game.