I think I might have "broken" the game. after numerous defeat at the boss level due to my inferior reflex (to aim at that tiny window of opportunity whilst protecting the city), I "accidentally" sold my jammer and interceptor building to obtain more machine gun and rail gun. now I'm stuck in heaven/oblivion with everything charged up but no enemies in sight on "Day 4" ...
But great game! with the extra stuff you get after losses, you managed to make a difficult shooter game enjoyable for someone who serious suck at nonautonomous video games in general