It sucks when players have to actually BUY upgrades, weapon packs, levels, etc... in order to enhance gameplay. Why can't we just play the game as it should be?
Actually the boss is quite easier than levels 8 and 9. Nevertheless, getting 150, 000 points is impossible. It would take forever to kill 15, 000 blue ones, and I'm sure I'm not the only one who doesn't like a window full of shooting purple stars.