Metal Slug introduced a pair of scrappy soldiers, Marco Rossing and Tarma Roving. The characters were largely interchangeable but they fit into the story as members of an elite group tasked with shutting down the operation of General Morden. Only in pacifist, government-controlled Japan could a storyline originate where the soldiers of the government are straight arrows fighting against a power-hungry rebel force. Rossing and Roving are members of the so-called Regular Army charged with defending the country. The Rebellion Army led by Morden overwhelms the Regular forces and steals a prototype tank called the
Metal Slug. With the Rebels intent on turning the country into a military state, it is critical that all
Metal Slug vehicles be destroyed or recaptured.
The subsequent games were built around variations of this storyline. Some pieces of the story that became Metal Slug staples included the idea of playing multiple characters, rescuing prisoners, piloting vehicles, and destroying enemy firepower. Morden and his troops continued to mobilize throughout the years and needed a thumping not once or twice, but six more times! The second game introduced two new characters, Eri Kasamoto and Fio Germi, that appeared in later games. The idea of switching between characters for practical rather than novelty reasons popped up in the sequel. The other story element that changed some play dynamics for Metal Slug 2 was aliens. Apparently Morden enlisted some aliens (yes, aliens) to his cause in hopes of overpowering the Regulars. Fighting aliens and commandeering alien technology makes for some very interesting diversions from the original Metal Slug. The third game in the sequence is actually a rev of Metal Slug 2 with some improvements. The actual Metal Slug 3 is a fourth release that retained all the characters and featured some improvements in play mechanics and design. Metal Slug 4 briefly swapped Nadia Cassel and Trevor Spacey for Kasamoto and Germi, but Kasamoto and Germi return in Metal Slug 5. Both these games take focus away from Morden and the Rebel forces to introduce other threats to national security. The themes of the Metal Slug games moved toward more high-tech enemies and more complicated environments as the game-design horizons expanded. The final game in the series, Metal Slug 6, is seeing its first release in this collection. The depth of this entry is outstanding, with six playable characters and every 2D trick in the book employed to make things immersive and challenging. This installment would justify a purchase even without the previous anthologized entries.
