Metal Slug 2001 is a single-player action, shooter, and platformer game in which players control a soldier fighting against enemy forces using a variety of weapons and vehicles. In this game, the storyline revolves around a military conflict set in a war-torn environment, with players engaging in missions to defeat enemy troops and complete objectives. It stands out with its fast-paced gameplay, detailed sprite graphics, and the incorporation of elements from the original Metal Slug series, adapted for the Game Boy Color platform, offering a nostalgic yet challenging experience.