Just wanted to share this with those who might be interested:

"In this video, you can see an early trailer that was made about two years before the final release. It shows animations that mostly appeared in the intro of the game, but ingame graphics and interface changed quite a lot."

http://www.youtube.com/watch?v=8C6B8W9EQUM&feature=youtu.be&a=

I still wonder if these early versions exist somewhere. I personaly would love to try them.

From the video it does look bare bones but it kind of looks better than it finally looked due to the walls being in 3D

That's early alpha? I remember a trailer where the graphics was in 2-D.