You can now play 15 levels of Defensoid for FREE! Occasionally you'll be subjected to an advertisement, but never during actual gameplay. To support the ads, the "Internet" permission is now requested. It is only used to fetch advertisements, however.
This will be an ongoing experiment :) Perhaps more levels will be added if the response is good. Keep in mind that the full version has all 25 levels and no ads...and right now can be had for the low, low price of 99 cents!!!
Happy Defending. More updates to follow...my first priority has been changed from "global high scores" to "level editor". I think the latter is more important. Feel free to argue.