This game spelt the beginning of one of the greatest run and gun arcade series ever created.
Here's the story: In the year 2028, General Donald Morden seeks to lead his rebel army against the Regular Army and establish a totalitarian dictatorship. In response Captain Marco Rossi and Lieutenant Tarma Roving from the Peregrine Falcon Strike Force are dispatched to use new Metal Slugs to battle and defeat the rebels.
The gameplay follows the same side-scrolling shooting formula of Contra, R-Type, and Gradius. Your default weapons are a handgun and grenades, but you can wield a heavy machine gun, rocket launcher, and flameshot. You'll also have access to the titular Metal Slug, a one-man tank armed with a cannon and machine guns. The games combat is fast-paced and relies not only on accuracy and speed but enemy memorization and maneuvering, because just one hit will kill your character, so dodging projectiles and timing your jumps and movements can mean the difference between life and death, especially for those looking to beat your high score by collecting as many POWs as you can.
You'll traverse 6 gorgeous looking stages stretching from the jungles of Vietnam to snowy valleys in Europe fighting a steady stream of rebel infantry and vehicles including trucks, tanks, planes, and helicopters. At the end you'll defeat a boss at the end until they reach Morden himself.
The animation is beautiful and fluid, with hand-drawn levels and backgrounds. Plus, the sprites are very unique and some of the best looking I've seen in a 90s arcade game. The sound effects are intense and awesome, from gunfire, explosions, screams of dying enemies you'd expect in a shoot-em up' game. The graphics and animation were great for the time, water splashes, blood spurts from enemies, explosions and flying smoldering debris from destroyed vehicles and buildings.
The music was excellent. The triumphant sounding "Mission Complete" fanfare really filled you with a strong feeling of victory that got better with each new installment.
Any true 90s kid who loved arcade games has definitely played this, me included. Even today, it's enjoyable and available on Steam.