Two hours?
I just have a small thing to say to you: I spent two hours playing it.
The audio is not the best I've seen but it's OK.
The graphics are acceptable, good enough for a Defense Game.
The gameplay is alright and the controls are a bit simple. (well, in Defense Games the controls must be ALWAYS simple)
Congrats, mate, you deserve the 9 stars. I don't give you 10 because I'm not that into that thing of Defense and I've played better games of the genre.
Cheers and, once more, congrats.