The enemy regeneration is horrendous. I just spent half an hour trying to take an enemy structure, and their troops were regenerating so fast I was never able to put damage on the building.
Fix this now.
With the energy system, I really can only play this game for about ten minutes a couple times a day. Even a whole energy bar is good for only a handful of drills, and MAYBE enough for a game.
One or two people have mentioned this before. Does it happen every time?