I don't get it ... seems like a battle I can't win ... the light is always growing faster than I can produce dark bugs. Should I do something else? How do I "encroach on the light"?
you have to produce enough minions to make the light circle remain small. Then the darkness will start to get closer.
Then probably I just did not find the right strategy I guess, because no matter how many minions I produce, the light always wins. Ah well ...