A very detailled look at the history of Metal Slug, In the hunt and gunforce 2

Back in 2013, a French gamer made two extensive videos about the development history of Metal Slug and its two spriritual predecessors, In the Hunt and Gunforce 2, for his Youtube channel Retro Game Test. What made these videos notable is that the guy somehow managed to meet many of the original developers (I’m inclined to believe the claim is legitimate as the guy holds the graphic sheets for the original “tank” version of Metal Slug throughout the second video) and thus got a vbery deep look at the development, including the then-completely unknown first iteration of Metal Slug that was only set in the tank.

I had actually posted about the Metal Slug video wayyyy back on neogaf but not the ITH or Gunforce 2 portions… until now!

The videos:

On Irem in general

  • After the success of R-Type, Irem “rested on their laurels” and made more games using that formula. Fans of the company liked games like Ninja Spirit and X-Multiply, but “casuals” did not like the high difficulty level and lack of co-op gameplay. Recognizing this was an issue, Irem intended the games for their new M92 arcade board to be a “clean break” and appeal to a wider audience.
    (The video doesn’t make the connection, but I think this explains why R-Type Leo is a very different and more relaxed take on R-Type, I think.)
  • Super R-Type was a major financial disaster, especially for Irem USA. Basically: they expected the game to be a surefire success due to being a launch title in NA and produced 250k copies, and then another 50k for the after-Christmas period. Super R-Type was expected to sell at least 250k copies, but in the end it only sold 50k.
  • An unspecificed employee blame poor play-testing practices as one of the factors behind the company’s death: Basically: Instead of using “normal” players for location-testing, Irem had their arcade games tested by fans of the company’s previous games and hardcore fans of arcade gaming in general, who were much more skilled than the average player. These way above-average gamers made the games look “too easy” during testing so Irem adjusted the difficulty accordingly, but in tuning the game around the top 1%, Irem made the games too difficult to appeal to the average arcade-goer.
  • The developers deny the popular rumour Irem employees went to work to Aicom (the Viewpoint/Pulstar guys) to make Pulstar. Infact, it’s stated they “didn’t take kindly” to the game and saw it as rip-off made to fill the void of Irem’s death. Top Hunter and Last Resort are the actual Neo Geo games to have been made by former Irem employees.
  • The video confirms that the infamously shitty western release of Undercover Cops is literally a beta version of the game. What’s new is that none of the developer had any idea the game was released in that state outside Japan.
  • Irem liked used the numbver 8 on sprite graphics due to its cultural connotations and it being easily reversible.

Sales numbers

These sale numbers for Irem’s arcade games were given by Irem’s USA National Sales manager, Drew Maniscalco

Gunforce: 750 boards
Hammerin’ Harry: 100 boards
Major Title: 200 boards

On In The Hunt

  • Director Kazuma Kujo (aka NAG) was ordered to do a shmup by management. He considered himself a fan of the genre, but disliked some conventions like forced scrolling and the omnipresence of outer space themes with star backgrounds. He wanted to do something fresh, but spent months unable to think of a good theme. One day he took a nap in a park, and when he woke up, he saw a fountain. This is how he got the idea to make it underwater-themed.
  • The player vehicles were meant to be spaceships travelling underwater, but they were changed to submarines after many designers left for other studios.
  • The graphic designer was a big fan of Ecco the Dolphin and played it during development.
  • The original composer (HIYA! metal slug composer) was initially slated to be composer on In the Hunt but he had to Image Fight 2, which was regarded as a big project for Irem in part due to its use of anime cutscenes with voice acting. HIYA! spent a whole month working on Image Fight 2.

On Gunforce II

  • The development of the game was very troubled. They don’t elaborate on its problems, but basically, the original iteration of the game played poorly, looked bad, and the two designers who worked on it were “really bad” at their job. Staff meant for Hunt the Hunt were sent to salvage the project.

  • Talking about the graphics, the graphic designer says he didn’t have time to redraw the player characters sprites (outside of the motorcycle-riding section) and that they represent how the original iteration of Gunforce II looked like.

  • On the name: Some think the “Gunforce II” name was the doing of the US distributor, because the game is named “GeoStorm” in Japan and it doesn’t resemble the original Gunforce much, but that’s not the case at all. The game was always intended to be a sequel to Gunforce because that game was a success in the US (see the sale numbers above) and Irem wanted to make a game to help the ailing USA division.
    So why the “GeoStorm” name? Well, late in development, the director (Meeher) came in and announced the name of the game was now GeoStorm. He was close friend with the main composer (HIYA!), and as it turns out, Hiya’s car was a Geo Storm. Really.

  • On the music: The composer was brought in midway through development and didn’t have the time to make a brand new soundtrack. He saw the game and interpreted it as “the ground front of Air Duel”, and asked if he could just rearrange the tunes from that game, which the director accepted. [Incidentally, Air Duel would also find some of its themes rearranged in the Metal Slug series]

The plot of Gunforce 2
This is apparently the official plot of Gunforce 2 though they don’t specific where they got it from. It appears as tooltip in the first video at 36:37. I’m translanting it because I find it funny

“In 2004, the terrorist group DAS has completed its program ZETTAI NINGYO KEIKAKU whose goal is to create a new breed of much stronger humans capable of surviving in the vacuum of space… done by combining a bionic computer with the female XX chromosomes. The female population is in danger. You must rescue them. The name of the operation is GIRL HUNT”

*a friend told me this can be translated to something like “absolute puppet plan”

On Nazca
-Nazca was always a SNK joint. The Osaka game development community was tight-knit and SNK funded Nazca’s foundation to make us of Irem’s talents.
-Nazca was set up to port SNK’s games to he Saturn and Playstation. They inisted to be able to make an original arcade game. SNK allowed them to make it on their off-time.
-The developers took the dev kits they used with Irem when it closed. They disliked SNK’s dev tools and quickly set up “a more modern rig”.
-The two guys speculate Neo Turf Master was repurposed from a third Major Title game due to the obvious similarities and that one of NTM’s director is not credited in any games made after it. This wasn’t confirmed however.

Metal Slug Zero

The original version of Metal Slug was a very different game! Let’s see how

-The entire game was played with the Metal Slug. There was no pedestrian gameplay and Marco and Tarma did not exist at this point.

-The tone was more somber and lacked any humour, being more in line with the team’s work on In the Hunt.

-The backgrounds were redrawn. For example, the entire first stage, and not just the second half, was set inside a swamp.

-The game was much shorter: Stage 2 did not have an equivalent in the original version (Metal Slug Zero was supposed to have 6 levels like the final one, but the Kobe earthquake prevented one of the designer from coming over), and levels were shorter and simpler (for example, level 3 did not have the climbing portion or a mid-boss battle). The game was lengthened due to the poor recpetion at loke testing (see below), the developers later reasoning being that since the Neo Geo was also sold as an home system, the game should be of reasonable length.

-The original plot was that General Morden had spent years planning a coup and managed to conquer all of the world’s major cities in his opening salvo. The original player character, Phil John, was an engineer for the Regular Army who was working on the Metal Slug prototype, and took it with him to join the resistance. Player 2 was a gold Metal Slug piloted by a woman named Michiko Nakajima. (The video doesn’t mention it but concept art for what was very probably these two characters can be seen in the concept art gallery in the NGCD and 32-bits versions of Metal Slug)

-The bearded POWs originally were blue pallete swaps of the enemy soldiers. Furthermore, instead of giving items, rescued PO Ws would either climb to the top of the Metal Slug and fire their bazooka, or stay next to it and throw grenades.

-The prototype was completed and demo’ed at SNK’s Osaka location 1995. Magazines such as Gamest and Famitsu liked it, but the game got a poor reception from SNK management and Neo Goe fans, who felt it lacked the boisterous and “fun spirit” of the average Neo Geo game.

The video ends with the two guys teasing they may have found a lead on a prototype cartridge, but that “it’s a bit tenuous” and that “it won’t be until a long time”. There’s been no news since then.

Other fun facts about Metal Slug

  • Rearranged themes from Metal Slug 1 were composed for X and are still present in the ROM
  • Metal Slug X actually started development much later than Metal SLug 3.
  • A “X” version of Metal Slug 3 was planned
  • The antagonists of Metal Slug 4 would have been fish-people (as hinted in the ending of Metal Slug 3).
  • They also deny the Atomiswave game Dolphin Blue was intented as a spiritual successor to MS’ saying “only two MS developers worked on it” and that it was “a complete coincidence”.

The same channel made an interesting video about the development of Magician Lord and SNK’s early strategy for the Neo Geo, whose tidbits I’ll share when I find the time.


Great topic. I’ve loved In The Hunt for a long time. Hopefully it gets an Arcade Archives release.

Cool stuff.

The Super R-Type things sounds a bit weird and off. It was a pretty bad game with all the slowdown, which would have hurt it, but still seemed popular? 50k seems very low.

If they made that many carts they would have sold eventually too? Just like all Capcom’s ‘shipped’ figures these days, which include bargain bin sales for $5, except back then prices didn’t collapse as much.

Damn. I’m at a movie right now. But can’t wait to read this. Looks amazing

Thanks, need to put some time by to read this fully…

That was an interesting read. Thanks for taking the time to do this!

This was awesome. There’s just something about Metal Slug 1-3 + X that really stands out to me as very high quality. Like the best that 16 bit had to offer as far as visuals and gameplay are concerned.

The craziest thing is how smooth and detailed the animation looks despite the games only being 30fps. It really goes to show that sometimes the compromises of halving the framerate to serve the rest of the package actually CAN pay off and make for a better experience in some cases. In fact, it was a very long time before I even realized I’m playing a 30fps game with the first Metal Slug.

The developers really made something special.

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I think the reason this is the case is that it’s clearly inspired by traditional animation, which runs at 24FPS, much like film.

I don’t think so. Gunforce 2 has a similar style but runs at 60 fps (albeit with ton of slowdowns)

As do the beautiful DarkStalker games, which are very much traditionally animation inspired. It was more of a guess.

Thanks for the write up, this was a great and really interesting read! But I agree with D.lo. Im sure Super R-Type eventually sold much more, considering how common it is these days.

Thanks for posting! Very interesting. Some of the info conflicts with other reports however.

For example, Slopes Game Room claims that Nazca was formed because those particular Irem guys were fed up with Irem’s handling of the company and wanted to do their own thing. It was later when SNK scooped them up. I’m not sure who’s info is correct, btw. I just wonder sometimes how accurate any of these videos are.

Thanks for posting this! I was going through my old photobucket account recently and found this image. Best $150 I ever spent.


150? sounds like a good deal. The console ports are nearly that expensive too.

It was $150 for the cabinet with the game but this was in 2000. I’m amazed at the prices arcade games go for these days.

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Damn… wish I had the ability to jump on something like that back then… but I was like 13 at the time.

It’s all relative. I wish I had bought more NES and SNES games back when they were on clearance but such is life. I’m happy with what I was able to purchase.

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