From the PlanetXbox360 feature list:
"Shoot’em-ups (better known as Shmups) have seeming always existed in one incarnation or another and will no doubt continue to do so until people stop playing video games for the next best thing. Not because gamers enjoy a challenge or are secretly masochists yearning for a game to continuously beat them down until they curl up on their couch in the fetal position, a psychologically broken mess. But because at our most very basic instincts – we want to just destroy every single damn thing on the screen with any conceivable weapon we can. Thanks to the difficult learning curve in some titles as well as the preposterous time investment required by some, shmups will forever be more of a cult-genre. But, whether or not you love shmups or just looking to broaden your horizons to the inclusion of some heavy firepower – you should go ahead and give these titles a glance."