The more levels you complete, the more levels you can skip ahead.
Starting tutorials now have a very clear progress indicator. Some people got confused and stuck for a few moments, because they didn't use WASD/Left gamepad stick for long enough.
A new popup tutorial will show the first time you use the Rotation Tool if you are using Mouse+Keyboard controls.
Removed some decoration on levels 11 and 20, that obstructed the view too much.