If you appreciate the work done within the wiki, please consider supporting The Cutting Room Floor on Patreon. Thanks for all your support!

Metal Slug X: Super Vehicle-001 (Neo Geo)

From The Cutting Room Floor
(Redirected from Metal Slug X (Neo Geo))
Jump to navigation Jump to search

Title Screen

Metal Slug X: Super Vehicle-001

Developer: Nazca
Publisher: SNK
Platforms: Neo Geo, Arcade (Neo Geo)
Released in JP: March 19, 1999 (MVS), May 27, 1999 (AES)
Released in US: May 27, 1999
Released in EU: May 27, 1999

AreasIcon.png This game has unused areas.
GraphicsIcon.png This game has unused graphics.
DebugIcon.png This game has debugging material.
SoundtestIcon.png This game has a hidden sound test.
LevelSelectIcon.png This game has a hidden level select.
RegionIcon.png This game has regional differences.
PiracyIcon.png This game has anti-piracy features.

Metal Slug X is like the director's cut of Metal Slug 2, seemingly built from an early version of Metal Slug 3. The bombastic announcer makes its debut (RAWKET LAWNCHAIR!), and best of all, there are no more slowdowns! It's amazing.

To do:
  • Sub-page for unused enemies and other objects.
    • Some can be seen in the debug tests, however, there is much more stuff, as demonstrated by these hack ROM videos: [1] [2] [3] [4]
    • Find a way to access them by code cheating or ROM hacking.
    • Also add unused graphics from here: [5]


Unused Stages
A whopping 56 of them, in various stages of completion.

Debug Menu



  • メニューを とじる(PAUSEしたまま) - Close the Menu (While Paused)
  • ステージ セレクト - Stage Select
  • サウンド テスト - Sound Test

It is worth noting this Debug menu is shared by Metal Slug 2, X, 3, 4, and 5.

To access the debug mode, open the game in Console Mode and set debug developer mode On at the Neo Geo boot-up screen: this can be done via the Kawaks emulator, the Nebula emulator or using the Neo Geo UniBios.

Enter the game, and press COIN twice during gameplay: after pausing, the debug menu will appear - with options to activate the debug dipswitches (which can be activated separately through other options using Kawaks) and even the ability to play on any regular level, and even some test levels not available in the actual game. There is also a Sound Test screen and Color Test screen.

(Source: http://randomhoohaas.flyingomelette.com/msmia/debug/)



  • ムテキ - Invincibility.
  • VIEW INFORMATION - View debug information.
  • イツデモPAUSE - Allows pausing during score tally, cutscenes, and credits.
  • VIEW GEO SCROLL A - 1st plane check, shows the walkable ground, makes the foreground choppy as it scrolls when activated. May linger if not turned off properly.
  • VIEW GEO SCROLL B - 2nd plane check, makes the background choppy as it scrolls when activated.
  • VIEW ATTACK RECT - View attack hitbox.
  • VIEW BODY RECT - View body hitbox.
  • ムセイゲン グレネード - Infinite grenades.
  • ムセイゲン POWガン - Infinite ammunition.
  • VIEW PA ポイント - A sprite of Satiko Suzuki with the wrong palette appears, showing the player's respawn point.
  • Dボタン、テキ ゼンメツ - Press D to destroy all on-screen enemies (no score bonuses).

Stage Select

Exactly what it says on the tin, allows you to warp to all stages and sections in the game. Unlike Metal Slug 2, Metal Slug X contains a whopping 56 unused stages. Some of them were later used for Metal Slug 3 with major/minor spit and polish. See the sub-page on where does it warp to.



These strange test stages can be accessed with the above debug menu. While some of the test stages' names are the same as those of Metal Slug 2, they were completely different. There's also a couple of new names in the test stage selection.


  • TEST1 for ANDY THE WIZARD The start of Mission 1, claims that it's Mission 3. There's a POW with an Armor Piercer at the start, and another AP, followed by boxes of Shotgun, Rocket Launcher, Flame Shot, Laser and Enemy Chaser. A Girida-O is parachuted in right after the Enemy Chaser, and the rest of the test level is empty.
  • TEST2 for MEEHER will bring you to the start of Mission 4. The first thing you will see here is a rocket flying ass-backward (!) and a Camel Slug. Some mummy dogs and a runaway camel show up. Level doesn't scroll when the dogs are gone.
  • TEST3 for YOKO-SHU transports you to the start of Mission 3, but it claims to be Mission 5. Parts of the game's credit bizarrely scrolls up immediately after you spawn. The two sunbathing soldiers can be shot dead, who will drop a shotgun and a machine gun if shot some more. A Metal Slug is available ahead, and lots of those guardposts in Metal Slug shows up, some are bizarrely floating on air. A rocket well is right up ahead, and two Dararin Dara Daras can be seen (the first one is dumping steel beams to the ground, should the player didn't advance too fast). After the frogmen up ahead, the houses can still be destroyed for food items like the original levels. When reaching the boss area, the screen scrolls slowly as if encountering the boss, but the boss never shows up.
  • TEST4 for ナミひら (Namihira) starts off at a section of Final Mission, with an MH-6J Masknell flying in, and unlimited Slugnoids to the right. Some soldiers show up, and getting to the end of the stage will end the mission and brings you to the total score tally and straight to the credits.
  • TEST5 for アリタ (Arita) starts you off at the start of Mission 1, but swordsmen Arabs show up instead of enemy infantry. A group of coins may or may not appear, and later on the stage, a coin, a banana or a steaming pile will spawn out of nowhere for grabs.
  • TEST6 for NISHINO is Mission 4 claimed as Mission 2. Various armaments will be available at the start of spawn and things get weird from there. There are various enemies that would later appear in Metal Slug 3, such as the snail, the piranha, the foremen with plungers and the Japanese airplanes on ziplines. Like the YOKO-SHU test stage, upon reaching the boss area the screen scrolls slowly like when encountering the boss, but the boss never shows up.
  • TEST7 for NAKATUKA it's simply a Mission 1 claiming that it's Mission 3. There is no music, no props to jump on (e.g. the first building you see) like the original stage. Getting to the building with the three towers, you will fight Morden in a chopper. Taking him out will end the mission and continues off to the proper game, Mission 4 and beyond.
  • TEST8 for TAGUCHI is a section of Mission 2 claiming that it's Mission 4. There is a Slug Flyer at the beginning with a few mortar infantries. As you go up, various crabs will spawn from out of nowhere, and as you reach the last leg before the boss area, various coins, and mummy jars will spawn out of thin air. Like the YOKO-SHU and NISHINO test stage, upon reaching the boss area the screen scrolls slowly like when encountering the boss, but the boss never shows up.

Sound Test

SFX and BGM test screen.



Color test screen.


Region-exclusive Messages

Depending on what BIOS is used, the message shown at startup will be different.

US (MVS) Japan
MSX-USmessage.png MS5-JPmessage.png

Note the misspelling "ADVISOLY". Also, the credit amounts are showed in the screen, which is unusual.


To do:
More technical analysis welcome!

Mslugx warning.png

Metal Slug X uses a unique PROG board, PROGEOP, only used by this game, featuring an Altera CPLD and custom Toshiba "0103" chip for protection purposes, running a constantly running stream of challenge/response. Should the responses ever be wrong or out of sync, then the game prints an angry red message to the screen and hard locks.

Of note is that current emulator solutions like MAME don't successfully emulate this protection, in favor of patching it out in memory!

(Source: Neo Geo Dev Wiki)