There's two big things I really don't like about Sky Defenders. First, the game is basically a reskinned clone of the much better Tilt to Live, so if for some strange reason you still haven't played that one yet, go ahead and download the original and see how this "reactive shooter" genre is done. The second issue I have with Sky Defenders is that the game depends heavily on Facebook integration, so much so that when it first starts up, you're asked to log into Facebook right away, though you can still get into the game by hitting a small, gray "Play Offline" button. I really dislike being so pressured to be social -- maybe that's a reality for the developers, but
