-Interface improvements
-Improved font size and colorimetry
-Added volume option at game launch
-Addition of a "back to alpha site" button at the start of each level
in the towers and technologies selection menu
-Interact with heroes" section added to tutorial
-The middle mouse click (mouse 3) now switches the timer between waves, as does the "enter" key.
Update 14: Enjoy the little things!
Source: Steam Community (opens in a new tab)