Clicking on the powerups that "fall" out of enemies is tricky. Could use a "Buy 10" button. I've gotten pretty far into the game, let it run over night and don't see any kind of prestige system. The reward for spending billions of dollars on upgrades is just 500k. Doesn't seem right. Nothing left to do but try to achieve goals, but no big upgrades left to help me do it. Pretty fun game overall. The music sounds very familiar, but I can't quite put my finger on it.