A long time ago, I was in a summer program that went on for a few weeks. I enjoyed it, and one of the years, I met a leader who enjoyed Metal Slug. Fortunately, that same year, i was in the group that got to go to an arcade. He and I played some co-op Metal Slug, and let me tell you, it was really fun. Once we were done, I asked him what his favorite and least favorite were, and he said that 3 was his favorite and 4 was his least favorite. I don't remember...