Wonderful game, I had no idea a city builder could be this.
It'd be cool to be able to undo back to the start of a phase.
Minor complaint is that the end can be really tough if you don't have enough to do the atmosphere from the get-go. Reclaiming things that create your river network takes away the rivers and makes it very difficult to cash in.
I'm not sure if this makes sense from a gameplay perspective but I want to be able to keep windmills/water pumps around to maintain river networks while deconstructing other things in phase III. I don't personally think finding places to place pylons that don't mess up your river network is a fun sort of challenge. If keeping my river network around were easier, I could see myself using more ports instead of trying to rush straight to the drone.