I'm glad someone else had trouble with this. I lost level six twice before getting through. I'm up to level eight but I had to get some sleep last night. Clever game. Disappointing that the last level is (by accounts) not so good.
I typically don't like games where colors are involved. I just can't see the difference between the reds and greens. I can tell the neutral ones OK, but I usually have to wait until the bad guys attack so I know which ones are theirs. That adds a bit of difficulty!