It is not a bug, there simply are no puddles. It's just a change in textures ...
There are many things that have been seen in the trailers and in the game are
very different, I begin to think that the trailers were engine renders
prepared to appear certain things that are not yet implemented or close
to being ...
@taigcris
Look at the Milestones, there are many things that are 70% or more. Many of these things are already playable, but weren't in the tech demo. I think the tech demo is an early version of the map the devs work at