Decoration

Mist, Snow, Rain, Autumn Leaves, Rays of Sunshine for "seasons."

Just to put here and there on the land, to give some 'atmosphere' and make it look like seasons.

Changing the ground so it appears to have snow, or green leaves, or autumn leaves, or mud puddles.

Being able to place things on the ground and in the sky, such as piles of autumn leaves, scattered green or gold or orange and red leaves along the ground (not heaps of leaves, but randomly scattered.)

A rainbow, some areas of mists (similar to fog), some light rain across the screen, some random rays of sunshine.

Maybe some closer up snowflakes, along with sky dotted with snow in the background.