Metal Slug X, then. Just you (and maybe a friend) against the entire Morden army. But after six missions of pain, you realise that this isn't quite so one-sided. An entire alien race is looking to enslave Earth. Unbelievably, the Morden have sided with the aliens and the climactic battle is just you against the General -- he is commandeering an alien ship. You, obviously, defeat him. But is it over? No! The aliens take the General! They have betrayed their allies! The biggest Mothership in the entire world attacks you! It takes up the entire top half of the bloody screen! The Morden bring you a Metal Slug and help you to destroy it as it throws everything it's got at you. But you prevail -- destroying the Mothership! The General drops down, strapped to a heavy metal slab, and his men rejoice! Unfortunately, the slab falls over and crushes him. And then the game ends. Sheer. Brilliance.