Metal Slug 3 is, for many, the absolute peak of the run-and-gun and classic SNK's swan song: it shipped in 2000, months before the company's bankruptcy, with the original team pouring their soul into every pixel. Its big idea is branching routes: every mission offers alternative paths — submarines, yeti caves, zombie plantations — multiplying replayability like no other title in the saga. The zombie transformation, with its devastating blood vomit, and the final mission — an outrageous space assault lasting over twenty minutes — are already arcade heritage. Technically it pushes the Neo Geo to the limit: a 708-megabit cartridge, screen-filling bosses and a constant parade of fresh ideas. The original AES cartridge is one of the crown jewels of collecting: a short print run, worldwide demand and four-figure prices that keep climbing.