As an Expanded Game released in 1999, Metal Slug X refines the frantic 2D run-and-gun shooter experience inherited from its predecessor, focusing on intense platforming and rapid-fire combat against overwhelming enemy forces. This version is distinguished by optimized performance, fixing slowdown issues, and notably increasing the overall difficulty. Players engage in side-scrolling action, utilizing varied weaponry across challenging stages. Its core value proposition is delivering a technically polished and significantly harder iteration of the classic arcade formula, appealing to those seeking a demanding test of reflexes.
The gameplay is fundamentally rooted in intense 2D platforming fused with relentless shooting mechanics. Players navigate detailed, often chaotic environments, employing an arsenal that ranges from standard machine guns to powerful heavy ordnance. The objective remains constant: eliminate waves of enemy soldiers, complex mechanized units, and challenging, screen-filling boss encounters. The visual presentation is characterized by detailed pixel art supporting the fast-paced action.
As an expanded iteration, this version specifically targets technical performance, ensuring smoother action even when the screen is heavily populated with sprites and effects—a common issue in the original source material. Furthermore, the difficulty scaling has been notably adjusted upward, requiring greater mastery of movement timing and resource management.
Beyond the critical performance fixes, this iteration introduced several subtle yet impactful additions to the established game system. These new elements provide fresh tactical considerations for players already familiar with the base game, adding layers of complexity to the familiar combat loop without fundamentally altering the core arcade structure.
This classic experience boasts wide accessibility, having been ported across numerous systems including PC (Microsoft Windows), Linux, Mac, mobile devices (iOS and Android), and legacy arcade hardware like the Neo Geo MVS and AES, alongside releases for the Wii. It is also accessible via web browser interfaces.
Regarding post-launch content, this specific release is presented as a complete package. There are currently no officially documented Downloadable Content (DLC) packs or further standalone expansions available for this version.
The primary draw for veteran players is the combination of enhanced technical performance and the significantly increased difficulty. This offers what many consider the definitive, most polished, and toughest version of the core adventure, specifically testing the reflexes and pattern recognition skills of seasoned arcade enthusiasts accustomed to the original's mechanics.

Metal Slug X is an action shooting game released by SNK in 1999. It is a rearranged version of Metal Slug 2. Using Metal Slug 2 as a base, a variety of new weapons and enemies have been added. Furthermore, with position changes of bosses and more, the game's difficulty has been completely readjusted.

Metal Slug X is a run and gun video game in the Metal Slug series. The PlayStation version was released in North America and PAL regions by Agetec and features the same "Combat School" mode featured in the console versions of the first two games.