These are absolutely amazing! thank you for making them public, i am sure i will use some of them in one of my games, one way or another.

I am especially a fan of the liquid anims, they fit together really smooth as background tiles.

Hope you post some more! i would also love transparent background .png whenever possible, i can use grayscale as alpha mask in photoshop on one by one picture, but i haven't figured out batch/automatic processing yet, so if you know how to do it quickly i would really appreciate if you just posted them for us, or perhaps could give me a tutorial on how to do it myself.