Just one level is not enough for test play. Even so the teaching how to use portal gun is awful. The platform on player side is really small and it's eays to make mistake and fall into gap. Make it more clear that YOU CAN CONTROL THE GUN BULLETS BY PRESSING W. This is totally counter intuitve at first. So far you can't control which color of door you will be chaning what will backfire in later levels.
Pretty good graphic and sounds but with ne level we can't say much about if this is fun or not.