There are a lot of defense games, but there aren't a lot of them that have that undefineable quality that makes them truly addictive and enjoyable. The Gem Craft series had it, and so, it would seem, does bbff. Unlike many other defense titles, where you put your towers really seems to matter, and planning out your strategy and seeing it come to fruition is very satisfying. While the map visuals start to feel a little stagnant after a while (gee, this sure is some nice cloned terrain here that apparently makes up the entire kingdom), on the whole bbff is nicely presented. There's no story, but then again, the game doesn't really need one.
There are some minor annoyances; the game starts to drag with longer and longer, but you've got everything you're ever going to have from the get-go. 5/5