God rays effect
Cast rays of light from the top of the screen. This won't work well if shown on top of the background color of the scene. Be sure to use an object acting as a background or a floor.

Use Angle to change the direction of the rays and Center X/Center Y to move the point they originate from. Light and Gain control the length and brightness of the rays, while Lacunarity adds more detail and irregularity to them. Enable Parallel to make all rays point in the same direction (like distant sunlight) instead of spreading out from the center point.
Set Animation speed to a value other than 0 to make the rays shimmer and move over time.
Reference
All effects are listed in the effects reference page.