I would agree that it is more an experimental experience than a game. Although, in the mathematical sense, of course it is a game...
Little bug: when you sit down, it looks like the boulder is running over your body. (Ouch!) The person should be placed more to the front and in front of the boulder.
I didn't notice that the messages of other players can be heard before I read the reviews. Maybe a hint would be useful. Also, they are too distored to understand them. I also at first didn't notice that the "pattern" in the foreground were other players. But later it clicked... :D