I want to suggest an idea for trees that might give the impression they are swaying.
To add changing pixels to the tree sprites, I have tried to search for examples but it did not work out, best exmaple I can give now are christmss trees .gif files
since they can explain it in this case. Slight collor changes which gives the impression of swaying leaves.
Glitter effect which gives the illusion of sunlight.
So basicly a little bit of pixels changing in a way that makes it looks like there is movement and maybe some glitter effect which gives the illusion of sunlight.
Not sure if this even work for this game or if it has to much impact on the game performance but I have seen it before and it gives the idea the elements are around.
