Not a bad effort.
I like the concept. Very simple design and easy to play. However, it was far too easy. I raced through it completing most levels in under 10 seconds. I also found the music a little boring after a while. I think this could be a pretty good game if you worked on it a bit more.
Suggestions...
Maybe you could have different zones. Different backgrounds to keep interest with a different song for each zone.
More complicated shapes. Would have been nice to at least see a circle or two.
Different types of broadcasting towers. Perhaps one that could rotate a signal (like a lighthouse) or ones that could penetrate through certain barriers.
Anyway, all in all a good effort. I think you've got the basis here but could possibly have been a little more creative.