I like the water in particular. Still many features missing, like point lights you can move around. And I haven't given up yet on a realtime global illumination hack. I think this is mandatory today to make interior spaces interesting.
This seems a lot of work. Does it make sense to build your own renderer? My interests are more around content generation and management.
Having a custom renderer has some advantages. It makes it very easy to get any project going. Once this engine is packaged into some form of SDK, it will help that anyone can make changes, compile them and run them without any third party libraries (just the OS and OpenGL).
And then, looking at the problems you get when implementing a renderer gives you some perspective. That tiny pixel in the horizon should grow and become a fully volumetric rock. Understanding how these distant features can be produced by the shaders helps tie them down to their close-range volumetric representations.