Putting here too in hopes people notice this since this is only critical to understand thing that doesnt come out very well in the game.
Defensive Pillars have TWO hotspots in them:
GREEN CIRCLE Increase Power
YELLOW CIRCLE Shoot with the current Power (when 0, it was supposed to be unclickable, but there is either a bug, or I forgot to prevent it)
rest of the instructions you either learn by playing, or are not that critical to understand.