Tower defense games are one of my favorite things to play, and they are also in my opinion one of the harder types of games to develop.
As you said there are some rough edges but it is a promising base. I had fun trying to find the best strategy to win!
The music was a bit loud for me on load and at first I found it a cumbersome placing towers because I kept trying to place them right up next to the road. The art is very nicely done and once turned down the music was lovely.