Strange how my first attempt with a
screenshot just blew me out of sight. Then I took half the picture, tried to blend it mirrored/flipped on top and gave up.
Then I realized it was dosbox that screwed it up, so I took one printscreen, recovered the raindrops and gave it a three degrees turn.
In CorelDraw5 I can melt parts of them and after 27 degrees I had 10 frames. (max frames for animations dew to the zero).
I'm still amazed what you did with it, didn't expect to see the outcome so good.
Preach's method can work also, but I'm so ferocious when it comes to using entities for textures.