Invasion Slots is filled with special features and although I am not crazy about the symbols, they nonetheless payout in high numbers. The introduction to this slot will tell you the following: “Brace yourself because the day has come when earth undergoes a space invasion! Resistance is futile earthlings, surrender your planet. Don't listen to these aliens bent on destruction; you must defend earth. Trigger at least three scatter symbols, and you'll get to do just that in the Alien Invasion Bonus. Arm yourself with laser-protective shields and guns and fire away at the 15 UFOs that appear. These ships will reveal varying prizes that will boost your bankroll. With a progressive jackpot continuously accumulating funds, fighting aliens and saving humanity has never been so lucrative and exciting before.” Now that’s a cool intro!