Lock's Quest is by no means perfect. The touch controls have their drawbacks, especially when tapping specific turrets within the isometric view. The tower-defense genre is, by definition, a "rinse and repeat" cycle that may grow old with gamers. And the lack of online play is a bit of a letdown.
At the same time, 5th Cell has done a great deal right with an original property. The story is surprisingly deep and gripping. New abilities or turrets help mix up the gameplay and provide gamers with refreshing approaches to each invasion. The visuals feel alive, with great animation and style. And if not enough, the epic soundtrack heightens the plot's sense of scale. All of this is wrapped up as a great package for any DS owner.