Thanks for playing and for giving feedback! You are supposed to be able to roll under those walls easily, but unfortunately there is a bug where sometimes you bounce up and hit the red wall. There is at least a small reason to choose a faster speed because it allows you to get a higher score faster (score increases based on distance, but difficulty increases based on time. This means by choosing a faster speed you can gain more points before the difficulty ramps up). Although I still agree that there could have been more incentive to choose a faster speed.