Metal Slug X

Metal Slug X, fully titled Metal Slug X: Super Vehicle-001, is a 1999 run-and-gun game released by SNK as a remixed and rebalanced version of Metal Slug 2. Originally launched for the Neo Geo arcade platform before later arriving on PlayStation in 2001, it’s widely considered one of the most polished entries in the entire Metal Slug series. In this article, we’ll explore why this game exists, what changed from its predecessor, and how it became a fan-favorite among run-and-gun shooters.

Born From a Technical Problem

Metal Slug X wasn’t originally planned as a standalone release. It exists almost entirely because of a serious technical issue plaguing its predecessor, Metal Slug 2. That 1998 game suffered from severe slowdown during several of its most intense stages, with the hardware struggling to keep pace with the sheer number of enemies, explosions, and projectiles filling the screen at once.

Rather than simply patching the existing game, SNK chose to rebuild it using the more capable engine that would go on to power Metal Slug 3. The result was a substantially smoother, more polished version of the same core game, released under a new name: Metal Slug X.

Same Stages, Completely Different Experience

While Metal Slug X retains identical level layouts to Metal Slug 2, almost everything populating those levels was reworked. Enemy placement and item locations were completely rearranged, giving veteran players a noticeably different experience even on familiar ground. The game’s difficulty was also significantly readjusted as a result of these changes, making it feel like a meaningfully distinct entry rather than a simple technical patch.

Several new features were introduced as well, expanding what players could do during a run:

• Big and Super Weapons — Upgraded versions of the heavy machine gun, flameshot, shotgun, laser rifle, and rocket launcher dealt significantly more damage, with even more destructive variants available while transformed into the game’s “Fat” form.
• Stones — A new primitive throwable weapon dealing concentrated single-target damage, trading area coverage for raw stopping power.
• Extended Fat transformation availability — Unlike Metal Slug 2, where this comedic power-up was locked to a single mission, Metal Slug X allowed players to access it from Mission 3 onward.
• New enemy types — Including the first appearance of the Dog Mummy, along with several mummy variants that would later reappear in Metal Slug 3.

The game also replaced its previous announcer voiceover with new audio that better reflected the expanded arsenal of weapons, a voice that would go on to be used in the series all the way through Metal Slug Advance.

New Modes for Dedicated Players

Metal Slug X introduced two standout modes that added meaningful replay value beyond the core campaign. Combat School tasked players with racing through missions as quickly as possible without losing a single life, all in an effort to impress in-game instructor Margaret Southwood. Another Mission, unlocked only after completing the main game, offered twenty unique challenges, ranging from finishing a level completely unarmed to defeating every enemy using nothing but grenades.

From Arcades to Home Consoles

Metal Slug X first released for the Neo Geo MVS arcade platform in 1999, with a Neo Geo AES home console port following shortly after that same year. The PlayStation version arrived later, launching in January 2001 in North America and PAL regions, published by Agetec. This PlayStation port carried over the Combat School mode that had previously appeared in Neo Geo CD versions of earlier games in the series, giving console players access to the same expanded content arcade and AES owners had already enjoyed.

Critical Reception and Lasting Praise

Metal Slug X was well received by critics, many of whom highlighted its sharp sense of humor as a defining strength. GameSpot praised the game’s tongue-in-cheek presentation, pointing to small details like enemy soldiers laughing when the player dies, only to shriek in terror upon realizing the player has respawned. This kind of irreverent, almost cartoonish charm, paired with the game’s frantic, high-energy action, helped it stand out even among other strong side-scrolling shooters of its era.

The PlayStation port specifically earned praise for being a faithful, fan-pleasing update to the Metal Slug formula, even as some reviewers noted that its presentation already felt a bit dated by the console’s later standards. Commercially, the PlayStation version sold over 95,000 copies in Japan and roughly 69,000 in the United States, for a combined total exceeding 164,000 units across both regions, a respectable performance for a niche arcade-style shooter on home consoles.

A Lasting Legacy Within the Series

Metal Slug X has continued to live on well beyond its original release window. It was included in the Metal Slug Anthology compilation released for Wii, PlayStation 2, and PSP, bringing it to an entirely new generation of console players. The game has also seen numerous further re-releases over the years, including digital storefronts on PlayStation Network, Steam, and modern consoles, ensuring it remains easily accessible to fans decades after its original arcade debut.

Final Thoughts

Metal Slug X stands as a rare example of a technical fix turning into something genuinely beloved in its own right. By rebuilding Metal Slug 2 on stronger technical footing and layering in new weapons, enemies, and modes, SNK didn’t just solve a performance problem, they created one of the most polished and frequently celebrated entries in the entire Metal Slug series.

Metal Slug Series in Release Order

1. Metal Slug (1996)
2. Metal Slug 2 (1998)
3. Metal Slug X (1999) – An enhanced version of Metal Slug 2 with improved performance, gameplay balancing, and additional content.
4. Metal Slug 3 (2000)
5. Metal Slug 4 (2002)
6. Metal Slug 5 (2003)
7. Metal Slug 6 (2006)
8. Metal Slug 7 (2008)
9. Metal Slug XX (2009) – An upgraded version of Metal Slug 7 featuring a new playable character, extra missions, and additional content.

Spin-Off Games

• Metal Slug: 1st Mission (1999)
• Metal Slug: 2nd Mission (2000)
• Metal Slug Advance (2004)
• Metal Slug 3D (2006)
• Metal Slug Defense (2014)
• Metal Slug Attack (2016)
• Metal Slug: Awakening (2023)
• Metal Slug Tactics (2024)

Recommended Play Order

If you want to experience the series in the best way, play the games in the following order:

1. Metal Slug
2. Metal Slug X (recommended instead of Metal Slug 2)
3. Metal Slug 3
4. Metal Slug 4
5. Metal Slug 5
6. Metal Slug 6
7. Metal Slug XX (recommended instead of Metal Slug 7)

Note: Metal Slug X is an enhanced edition of Metal Slug 2, while Metal Slug XX is the expanded version of Metal Slug 7. Most fans recommend playing these upgraded editions instead of the originals for the best gameplay experience.