Been playing the build and this IS a great game as iPad owners have said. The action is frantic and in your face and you can't just sit and watch your constently adding towers and finding what's best suited for the upcoming onslaught.
Yes, I've been playing and enjoying it. Have you done level 2-3 because i'm completely stuck, i thought the idea would be to get lots of plasma towers down but it's not working. Haven't come across any bugs but there is a lot of slowdown when lots of enemies are on the screen.
I haven't notice it but I'm on 1-4 I upgraded my ship and unlocked the towers but just to see how they are.