Heh...nice little effect I achieved using a method similar to Ashleys rain demo, but magnifying the clouds on the bottom layer....I actually did this without using a single event!
Has clouds on it, and a sprite that magnifies the clouds for the reflection it has on the rock
The grass layer (needs to use its own texture)
Has grass on it, a sprite that shows the shadow of the rock, and a sprite that masks out the grass to reveal the rock
The top most layer
This just has a sprite on it which colours the rock, allowing the reflection to also be tinted the colour of the sprite.
And thats it. If you applied that technique in a full game you could easily have lakes and shiny objects or really any kind of reflection effect. Sadly the grapics I used in this don't really demonstrate the effect all that well heh
Oh btw use the mouse to move the rock, and the arrow keys to scroll the background.
Require Pixel Shader 1.4 - if you cant run it go to application properties and tick 'run without pixel shader'....it still works just doesn't look as good