I found this game to be pretty good. My biggest gripe is that it's a bit too basic. It just seems like it just some simple images that show the same things. I probably would still recommend it, because it's easy to understand. I also just happen to like defense games. I don't know if it's spelled with a C or an S.
The music was okay, if a tad redundant. There were some interesting things going on. You really do need to work on more detail. Just simple circles don't mean much. At least it's organized.