I really like tower defense games (heck, I made one as well), and this one was such a joy to play through. Great presentation.
Too bad you haven't managed to do something extra with the loops, as currently they're mostly just a replacement for a simple cooldown timer. But still, I really like what I see, and I think your planned feature of the player being able to move the loops and similar is a great foundation to work off of. I wish there were more levels!
Good job (with the font as well!). :)