The only feedback that I could possibly procure from such an awesome experience is that the red death zones were a bit painful. You travel faster than your heartbeats do, so I often collided with the red zones before I even knew they existed. Otherwise, awesome game, with effective use of simplistic graphics!
Thanks for the feedback! It was hard for me to find the right balance because if the player always see the red part, it would have been too easy with no surprise. But I understand the frustration of having to wait, one of the reviewer interpreted that as: patience is part of love. I thought that was brilliant ;)