Portal 2 Challenge: Cube Momentum

Just me having fun running through the Portal 2 Challenge mode. I have no illusions that I will ever have the fastest time, nor in many cases the fewest portals. Yes, I know it's possible to flip up the panel at just the right time and—with a lot of luck, I assume—get the cube to bounce up by the door. I don't know that I'll ever achieve that, but maybe I'll try some time.