Shooting fans think of one thing when they hear mention of Treasure: Radiant Silvergun. And that's probably what you'll think when first sinking your hands into Ikaruga; it is codenamed "Project RS-2", afterall. However, while the games share the same top-down vertically scrolling perspective (with bits of camerawork thrown in to show your ship zipping around the world from time to time), they're markedly different beasts, with this new entry incorporating ideas from another Treasure classic, Silhouette Mirage.