I spent a lot of time on volumetric clouds:
v=rMqIZMjhh0k
There are some pretty mirror-y metallic blocks, but nothing that’s a perfect mirror. It’s limited by the screen-space reflections.
Water/lava would be cool, as would be glass, but I don’t support translucent bricks yet. That part’s easy, but it might be hard to get good lighting on translucent surfaces. It would also be a bit of work to make water/lava affect player movement, and flow like in Minecraft.
I’m not planning to do anything smooth, sorry! I’d be happy to write up what needs to be changed if you (or anybody else) wants to do it.