Might as well share this. Made with Unity3d (free version of course). I made use of particles. Simple to make. Tell me what you think, and stuff I could add.
Cool, I haven't touched particles yet. I know you only have the met basic version like me, but I think it would be cool if the edges of the pool looked a bit craggier, as if chunks of rock had fallen in or collapsed from the sides. These areas could be a bit more jagged and would peak up the shore line a bit. By the way, is there anything outside the crater?