Time for a big patch with lots of changes and improvements! Note that even if you can continue your 6.1 save, I strongly suggest you start fresh. Many changes in the Tech Tree and heavy changes in the economy. A big addition, is the Undo button: if the game is paused and you place a building, simply hit Ctrl+Z and it's removed! Works with many buildings as well.
Please let me know how you feel with the huge amount of changes to the economy!
As usual, to access:
RightClick the game in your Library
Properties
Betas tab
Choose "publicbeta" in the dropdown
Close button
Let it patch
You can find the changelog here: https://steamcommunity.com/app/671440/discussions/4/2572002906845633729/