Very interesting concept, a lot could be done with this. At level 3 I was unable to turn around at all so I was unable to play that level. Also your choice of having the player colour the same as the background was fine but it looked bad when the edged of the player sprite overlapped the edges of the corridors. Also the white dots were clear but the gates were very hard to see, on the second level I completely missed what interacting with the square did. Zooming in so that everything was a big bigger on screen would have helped with this.