I think this is a cool idea, but of course it needs more development. Some things I noticed:
- When you start, the animation moves fast. The first time I tried, I blinked and suddenly the entire screen was filled with fire and water and I couldn't really tell how it got there.
- The first six or seven attempts I made, the left side filled with water, and the right side ended with some fire, some dirt (the pale brown is dirt, right?), and some water. But I couldn't really understand why the water would sometimes spread over dirt, but clearly not all the time.
- Similarly, on later levels, I wasn't always sure how things spread. (Did oil move faster than water or was that my imagination?)
The concept is great, and I think with a little tweaking to make things clearer to the player, it'll really come together.