First off, beautiful game.
Secondly, I had no clue what I was supposed to do. The aim of the game, fighting off the infection, doesn't appear in the actual game as far as I am aware, so I just wandered around aimlessly exploring.
It was still enjoyable because it was so darn pretty, but I really feel as though you guys should include directions in-game.
Perhaps a cut-scene at the start will do?