Thanks! I had to make use of that Bachelor's of Engineering Science somewhere.
I think having the electric field lines could make the screen feel a bit cluttered and might scare people away. Plus then I'd have to actually model the shape of electric field lines instead of just typing out Coulomb's Law in Lua.
Limits on drones or how many Coulombs you can use could have been good. Or possibly a scoring system which rewards using as few drones as possible.