I love this mechanic! Actually thought about making a similar concept game in the past.
Just some impression on the control scheme...
I find it little bit weird of the control. Subconsciously, I cannot easily convert my W/S feeling into Anti-clock/Clockwise. (Since they are not really uplift/ downward force...)
Since A/D is useless inside pink zone, do you think we can simply use A/D to control the rotation? Because when you describe how a clock hand moves... usually you think right = clockwise, left = anti-clockwise....
Btw, are the pink drill zone made up of many small objects?