Both games are very polished, especially for indie games, with nice GUIs and online highscores. You needn't worry about having to exit mid-game either, as the games will resume where you left off. The games even feature some catchy and haunting synth tunes. If Tech-Gaming had to pick one, they would recommend Blue Attack! but the games go great together, Blue Defense! being more reflexive and Blue Attack! being more strategic. They consider Blue Attack! to be one of the best iPhone/Touch games yet, and Blue Defense! is a good companion game.