Defender is one of the best known and most successful free games for Android phones. You can easily grab it over at the Android Market. Then again, you are probably aware of that, just as well as you are aware of the fact that Defender is a pretty unique take on the tower defense genre, complete with spells and a user controlled bow. What you probably aren't aware of are my thoughts on the thing, so, uhm, here goes.
Well, I do believe it's a very polished and interesting freebie, that could have been so much more. Not that it's not addictive mind, it most definitely is and has already eaten away over 10 hours of my time, but, well, so is FarmVille apparently. It's a good-looking grind, requiring minimal thought and minimal dexterity, yet one that can at times feel immensely enjoyable. Odd, I know, what I guess it's one of them games you'll have to try out.