Maybe add the possibility to placing water and adding some estructures like ducts to guide the water, adding waterfalls like decortive feature would be nice too
There are already some watery based things in the game (drains), so chances of a liquid pumping system looks promising.
If they let you start moving liquids with a water gun (Like I've seen in the news for the game) then they're pretty much forcing themselves to introduce pumps... people will beg for em
