You alter gravity for yourself, causing you to reorient which way is down for you until the end of your turn. You can pick any direction to fall as if under the effect of gravity, falling up to 500 feet before the spell ends. If you collide with something during this time, you take falling damage as normal, but you can control your fall as you could under normal conditions by holding onto objects or move along a surface according to your new orientation as normal until your turn ends and gravity returns to normal.