I. Game Background
1.1 World Setting
In the year 2028, the world is once again shrouded in the shadow of war. General Morden and his rebel army have returned, amassing a massive military force to overthrow world governments and establish a dictatorship. The elite soldiers of the Peregrine Falcon (PF) Squad—Marco Rossi, Tarma Roving, Eri Kasamoto, and Fio Germi—are deployed once again to execute what seems like an impossible mission.
Compared to Metal Slug 2, the plot framework of Metal Slug X remains largely the same, but the entire gameplay experience has been completely overhauled. Enemy deployments are denser, attack patterns are more diverse, and ambushes are placed in more devious locations. From Middle Eastern cities under the cover of night and deep abandoned factories to frozen Arctic bases, eerie prehistoric ruins, and floating alien motherships—the flames of war burn from Earth to outer space. Every battle is the ultimate test of a player's reflexes and patience.
1.2 Development History
Released by SNK in 1999, Metal Slug X is an enhanced version of Metal Slug 2. In an era of fierce arcade competition, SNK chose a pragmatic path: rather than creating a completely new game, they systematically reconfigured levels and optimized difficulty based on Metal Slug 2. This approach was known at the time as an "Enhanced Version," similar to how Street Fighter II': Champion Edition related to Street Fighter II.
This title uses the same MVS (Multi Video System) board as Metal Slug 2, keeping the core graphics and sound effects unchanged while making significant improvements to gameplay. Most notably: the game completely resolves the famous "slowdown" issue from Metal Slug 2. In the original, the frame rate would drop significantly when many enemies and explosions appeared on screen, severely affecting control responsiveness. Metal Slug X achieves a smooth 60 FPS throughout by optimizing sprite rendering logic and streamlining redundant data.
Furthermore, while Metal Slug X follows the basic framework of Metal Slug 2, almost every enemy placement, item location, and weapon drop has been rearranged. Veteran players of Metal Slug 2 will have a subtle, uncanny feeling: the levels look the same, but enemy spawn points are completely different. Safe paths may now be traps, and previously unreachable items are now easily accessible. This "familiar strangeness" is the game's most ingenious charm. Due to its high quality and precise fixes to the original's flaws, it is widely considered by hardcore fans to be the most replayable entry in the Metal Slug series.
II. Character Profiles
2.1 Marco Rossi — Balanced Commando
| Attribute | Rating |
|---|---|
| Power | ★★★ |
| Speed | ★★★ |
| Skill | ★★★ |
Marco is the assault captain of the PF Squad, boasting the most balanced ability profile. His stats are consistently above average with no obvious weaknesses, making him ideal for both beginners and advanced players.
Pros: Balanced stats with no fatal flaws; his grenade trajectory is relatively flat, making it easier to hit distant targets. Cons: Lacks a unique specialty, making him less flashy than Tarma or Eri in the hands of experts.
2.2 Tarma Roving — Vehicle Expert
| Attribute | Rating |
|---|---|
| Power | ★★★★ |
| Speed | ★★ |
| Skill | ★★ |
Tarma is a vehicle operation expert. He possesses higher shooting precision and faster fire rates when piloting tanks, planes, or camels. His background is that of a PF intelligence and vehicle specialist, known for his calm and cool-headed personality.
Pros: Extremely high output in vehicle combat; the best choice for vehicle-heavy stages. Cons: No significant advantages on foot; slightly larger hitbox than other characters.
2.3 Eri Kasamoto — Explosives Expert
| Attribute | Rating |
|---|---|
| Power | ★★ |
| Speed | ★★★★ |
| Skill | ★★★★ |
Eri is an intelligence agent for the PF Squad who specializes in throwing weapons. Her grenade trajectory is flatter and longer-ranged than others, and her throwing speed is faster, allowing for massive burst damage in a short time.
Pros: Unrivaled in grenade combat; high burst potential against dense enemies and bosses; fastest movement speed. Cons: Handgun damage seems slightly lower than other characters (though not officially confirmed); requires high precision to play effectively.
2.4 Fio Germi — The Lucky Recruit
| Attribute | Rating |
|---|---|
| Power | ★★★ |
| Speed | ★★★ |
| Skill | ★★★ |
Fio is the newest recruit to the PF Squad. Her abilities are standard, but she possesses a highly coveted hidden trait: her item drop rate appears slightly higher than other characters. Many players report that it is easier to obtain powerful weapons like the Heavy Machinegun and Laser Gun when playing as Fio.
Pros: Higher item drop rate (community legend, not officially confirmed); popular character design. Cons: No standout specialized abilities; her "recruit" status makes her less favored in high-level competitive circles.
III. Controls
3.1 Basic Controls
| Action | Key | Description |
|---|---|---|
| Move | Arrow Keys | 8-way movement |
| Attack | A | Fire current weapon |
| Jump | B | Jump, can change direction mid-air |
| Grenade | C | Throw a grenade (consumes stock) |
| Jump Attack | B + A | Attack while in the air |
| Crouch | Down | Reduce hitbox size |
| Board Vehicle | Move close | Automatically enter tanks/camels/planes |
3.2 Weapon System
| Weapon | Name | Characteristics |
|---|---|---|
| Handgun | Handgun | Default weapon, infinite ammo, low power |
| Heavy Machinegun (H) | Heavy Machinegun | Rapid fire, the most common transitional weapon |
| Rocket Launcher (R) | Rocket Launcher | High power, wide blast radius, great for bosses |
| Flame Shot (F) | Flame Shot | Melee powerhouse, instant kill for close-range enemies |
| Shotgun (S) | Shotgun | High close-range burst, fan-shaped spread |
| Laser Gun (L) | Laser Gun | Pierces enemies, long active hit duration |
| Enemy Chaser (C) | Enemy Chaser | Auto-tracking missiles, very helpful for aerial combat |
| Iron (I) | Iron Lizard | Highest power weapon, very limited ammo |
| Stone | Stone | Turns enemies into statues (limited versions) |
3.3 Vehicle Controls
This game inherits and expands upon the vehicle system from Metal Slug 2, adding new actions for certain vehicles:
- SV-001 Tank: Main cannon + heavy machinegun fire; can crouch to avoid bullets
- Slug Flyer: Aerial vehicle, free flight, fires left and right
- Camel: Rideable with mounted gun, can be replenished at specific spots
- Slug Gunner: Walking mech with a wide attack range
IV. Level Walkthrough & Boss Strategy
Stage 1: Middle Eastern City — Night Raid
| Scene | Boss | Strategy |
|---|---|---|
| Middle Eastern town at night, streets filled with cover and enemy troops | Hi-Do — A stationary turret equipped with two heavy cannons | Use buildings as cover and keep moving to avoid being locked on. The boss fires tracking missiles periodically; dodge in advance. Heavy Machinegun is recommended to suppress the cannons. |
New Configuration: Compared to MS2, enemy density is higher. Watch out for soldiers jumping out of windows; keep moving vertically and avoid walking in straight lines.
Stage 2: Underground Factory — Steel Labyrinth
| Scene | Boss | Strategy |
|---|---|---|
| Abandoned underground factory with conveyor belts and mechanical arms | Tani Oh — Large walking mech equipped with multi-tube missile launchers | There is a famous "escape" segment; climb upward quickly. During the boss fight, the far-left ground position is safe. Use ground cover when the boss fires full-screen missiles. Recommended: Rocket Launcher. |
Stage 3: Arctic Base — Frozen Hell
| Scene | Boss | Strategy |
|---|---|---|
| Polar military base, alternating between outdoor blizzards and indoor corridors | Dragon Nosuke — Heavily armed helicopter | Movement is slightly slowed in outdoor snow. Clear enemies in corridors before advancing. The boss fires many missiles and performs dive attacks; jump to dodge and focus fire on the cockpit. |
Stage 4: Giant Object — Mysterious Ruins
| Scene | Boss | Strategy |
|---|---|---|
| Suddenly appearing prehistoric land filled with giant insects and plants | Dragon Fly — A giant mutated mantis | This is the most visually striking stage in Metal Slug X. The atmosphere is eerie and grand. The boss attacks with scythe slashes and venom sprays; maintain a medium distance. |
Stage 5: Alien Mothership — Space Abyss
| Scene | Boss | Strategy |
|---|---|---|
| Inside the alien mothership, corridors filled with biological matter | Mars Alien Ship — The core guardian of the alien mothership | The terrain is extremely narrow; avoid retreating as enemies often spawn behind you. Deal with small enemies first before focusing fire on the boss. |
Stage 6: Final Battle — Morden's City
| Scene | Boss | Strategy |
|---|---|---|
| Rebel stronghold, atop the high tower | Final Boss — Alien Entity — The alien parasite inside General Morden | Divided into three parts: climbing the stairs, corridor combat, and the tower-top finale. The boss uses tentacle sweeps, lasers, and psychic waves. The boss has three phases, each increasing in speed. In the final phase, the core is exposed—dump all your Heavy Machinegun ammo here. |
V. Tips & Advanced Strategy
5.1 Basic Survival
- Weapon Management: Don't swap good weapons immediately. Save the Laser Gun and Rocket Launcher for boss fights.
- Hostage Rescue: Rescuing hostages grants items or score bonuses. Saving as many as possible is key to high scores.
- Don't Hoard Grenades: Use them decisively against dense groups. There are plenty of supply points.
- Master Jump-Shooting: You can attack while jumping; use this to suppress enemies and minimize ground hits.
- Understand the "Fat" Mechanic: Eating too much food makes you fat—higher attack power but slower movement. It's a double-edged sword during boss fights.
5.2 Co-op Tactics
- Clear Roles: One player suppresses fire, the other clears flanks. Recommended: One uses Heavy Machinegun, the other uses Shotgun or Flame Shot.
- Rescue Priority: Clear enemies before reviving teammates to avoid a "revive-die-revive" loop.
- Vehicle Co-op: One drives the tank, the other rides on the back to provide auxiliary fire—the most efficient co-op method.
5.3 Boss Fight Rules
- Clear Minions First: Most bosses spawn minions; prioritize clearing them.
- Predictable Patterns: Every boss follows a fixed pattern; observe for 2-3 cycles to master the rhythm.
- Cornering: Pushing a boss to the edge of the screen limits their movement.
- Handgun Backup: When out of ammo, the Handgun is reliable—low power, but infinite.
5.4 Advanced Knowledge
- Weapon Respawn: Weapons respawn after you die. Use this in specific stages to get double powerful weapons.
- "Infinite" Combos: Some bosses have "stun frames"; continuous output during these frames can skip certain boss attacks.
- Slide Dash: While there is no dedicated slide button, jumping while crouching creates a fast movement similar to a slide.
VI. Trivia & Arcade Legends
6.1 "Slowdown Disappears" — The Core Selling Point
Metal Slug 2's biggest flaw was "slowdown." Metal Slug X optimized sprite rendering and memory management within the MVS hardware limits, almost completely eliminating this. It is said that SNK engineers rewrote most of the core rendering pipeline code to achieve this.
6.2 The Art of Item Placement
Almost every item location in Metal Slug X was redesigned. The dev team spent months adjusting drop locations and types so players would constantly discover new strategies upon replaying.
6.3 "Hidden Hostages"
Metal Slug X features hidden hostages that require specific actions to trigger. For example, in Stage 2, throwing a grenade at an empty-looking wall reveals a secret room. This "Secret Rescue" design sparked a massive community hunt for hidden elements.
6.4 The Cultural Symbol of "Fatness"
The "Obesity Transformation" is a classic comedic element. While absurd, it became a beloved meme in the Metal Slug community—the image of a "fat character jumping to stomp enemies" is iconic.
6.5 The Mystery of the MS2 Relationship
Is it an upgrade or a standalone game? While it reuses MS2 map assets, the enemy configuration, weapon balance, and difficulty curve make it a completely different experience. If MS2 is the first draft, Metal Slug X is the final cut.
6.6 Ports & Remakes
After a rocky road to home consoles, the game finally received perfect ports on Nintendo Switch and PlayStation 4 via the Arcade Archives series, supporting save states and online leaderboards.
6.7 Speedrunner's Favorite
On Speedrun.com, Metal Slug X is one of the most popular titles. Experts use precise route planning and weapon management to clear the game in 15-18 minutes, with world-record holders pushing under 13 minutes.
