Game rocks but even harder than the first. I think there should be a mode where you can be invincible if you want, but you get no score and no (potential) badges if they are added. I want to see how the storyline progresses but im simply not good enough to beat it. I beat the first one after weeks of playing but this one is much harder. Other than that personal issue (its not a game flaw, i know its meant to be hard), 5/5 for sure. Good work man.. great engine and setting.
Heres how i beat Response 3 on Normal: http://img411.imageshack.us/img411/2484/response3a.png <---- trap the ship in the middle cause thats where it goes at first no matter what. then it has to choose each of the 4 corners to go kill. while its doing that, the other towers are all firing on it.