Cool game, I get that the turret needs to recharge after running out, but it was really frustrating sitting there watching the missiles destroy the city as I was helpless. I think I definitely does fit the theme, but maybe toning the difficulty down, showing when the turret is 'reloading', and tweaking the reload and max shots per reload would make it alot more fun. I like the idea of defending the city using it's energy, it's clear that the theme "everything has a cost" was used, nice!