
Not long after, a newly designed tank, code named “Metal Slug”, was forced into production. Seeing their disadvantage to carry out direct attacks against the Rebellion, the Regular Army then decided to carry out numerous special operations and create certain vehicles to accompany their commandos. With superior numbers of troops and weapons, the Rebels overwhelmed the Regular Army in all aspects. The fault was mostly in the hands of the Regular Army commanding officers, who failed to realize the value of information that the Regular Army intelligence division had provided. No one expected this except for the Rebels who came up with these plans. In 2026, the Rebellion Army launches an assault that pushes the Regular Army forces into the brink of destruction. The Rebellion is formed by a group of people whose wishes are to change the world government into a military controlled one. The Regular Army is a government run military force used for various tasks such as peacekeeping and fending off terrorism. After them is the boss of the stage, the Tetsuyuki.At the beginning of the 21st Century, two military groups known as the Regular Army and the Rebellion are at war.

In the last part you finally reach a waterfall, where are two Girida-O. Defeating it make it crash onto the building, revealing a TNT barrel being protected by some bazooka soldiers. As you kill both, another R-Shobu appears. You will reach the first Metal Slug, and two soldiers throwing grenades from a building. You can shoot the yellow barrels to explode the buildings and drop the big rocks over the soldiers. In the second part you go through a river inside the forest. After the Middle-Son, a R-Shobu will show up, just shoot him while dodgin his bombs. There is a Flame Shot crate, but it's better to keep the HMG since this stage is very generous on it. Some fanatic infatry are there hanging around, so the best way to finish them is by slicing them with the knife. Soon you will see the wrecked Middle-Son 1999. In the first part of the mission you're in some sort of ancient ruins. Lots of Heavy Machine Gun ammo are scattered through the stage, as well as prisoners, who are very visible, making it even more easy. Since it's the first mission from the very first game, it's very easy, serving more as an introduction to the game. Most of the mission is filled by rebel soldiers, with few vehicles here and there. Absolute Thick Forest is the first mission from Metal Slug: Super Vehicle-001.
