Toaplan STG Chronicle Q&A (2012)

Toaplan STG Chronicle Q&A (2012)

This is a companion to the Toaplan STG Chronicle interview that was bundled with the Toaplan STG Chronicle music collection. Its neatly organized by game and presents questions for each Toaplan shmup that Uemura and Yuge worked on. Unfortunately, this means that several of Toaplan’s other great games, like Outzone and Batsugun, are not addressed.

Tiger Heli

For Tiger Heli, we were aiming for a game where the stressful sections and the fun, exhilirating sections would be clearly delineated. We wanted a game that would make you want to play it again after you died, and make you think you could get just a little further. It turns out the replay rate on Tiger Heli was very high, so I think we succeeded in that goal.

Our PCB hardware then couldn’t do graphic transparencies, so we had all these tricks, like expressing an object’s shadow by high speed sprite flickering. We wanted the bomb graphics to be more detailed too, but that was a hardware limitation. (Yuge)

—Please tell us the history and reasons behind the decision to make the ship speed so slow.

Yuge: There’s a definite connection between high speed and that feeling of exhiliration, but if we made the ship faster, we’d have to make the bullets faster in order to keep the difficulty balanced, and we wanted to avoid doing that. We wanted beginners to be able to see the bullets clearly, so making the bullet speed slower was important. Another reason was that increasing the ship speed allows the player more freedom of movement, but that would mean that the make the routes the player could plan through each stage would become much more sloppy, and less strategic.

—At the time, including a “bomb” in a STG was a novel idea. Where did that idea come from?

Yuge: During development we kept asking ourselves how we could make things fun, and the bomb system was what we arrived at. We didn’t originally intend for it to be used by players as an emergency save. We added it as an aggressive, thrilling weapon you could use to turn the tables on the enemies with a single shot. It ended up being useful as an emergency save, too, but if you want to experience the strategy of the game as we planned it, its probably better not to use the bomb that way.

—In Tiger Heli, and about half of Toaplan’s other games, at the name entry screen, the background continues to scroll. What was the intention behind that?

Yuge: It was like a “sneak preview” of the next episode of a drama. We hoped players would see a little further ahead and want to play again. By the way, the way the tank’s cannons follow after the name entry cursor wasn’t done intentionally. It happened because we used the same sprite memory for the cursor that was used for the ship.

—Starting in the second loop, why do you start from stage 2, not stage 1?

Yuge: We thought stage 1 was too easy for successive loops. There’s too few enemies, and it wouldn’t be interesting to just speed up the bullets for them, so we skipped it.

—The background graphics in Tiger Heli have a style we would call “polygonal” today. Was there any reason behind that choice?

Yuge: Actually, around that time we were doing research for a flight simulator program we might develop. The designer used a sample image from that simulator in Tiger Heli. As for the simulator itself, we continued working on it up till the very end of Toaplan, but we never announced it publicly.

Slap Fight

Slap Fight’s appeal was to revolve around hidden items and the weapon power-up system; we wanted it to be a game you could play for a long time. We hoped people would play it again and again, trying to find all the hidden items and trying out the techniques they’d heard rumours about.

The way you became invicible whenever you changed weapons was meant to be one of the strategic elements of the game, also. Unfortunately, we had to use the same PSG chip as from Tiger Heli, so we couldn’t fulfill our ambitions with the sound until later. (Yuge)

—At one point did the capsule and gauge power-up system get added to the game?

Yuge: From the beginning. We started development knowing we wanted to make that kind of game.

—Regarding each weapon’s function and role in the game, how was that decided?

Yuge: We’d think of what weapon would be good for a certain part of the game, then we’d make sure there were enough power-ups for you to switch to it. If you’re aware of that, you can always have the right weapon for each section, and if you play enough you’ll probably figure it out.

—Slap Fight has so many hidden features. Were they all planned from the beginning?

Yuge: We knew we wanted to have some kind of hidden secrets at the beginning, and we kept adding to the idea as development progressed. The secrets that you need a certain weapon for were supposed to help you remember which weapon is best for a certain part. This idea later influenced us in Tatsujin, where we made it so you needed a specific weapon to get the 1UP.

—The ship option, another secret, can be controlled by a player sitting across from you on a cocktail cabinet. Who came up with that idea?

A: That was Lee Ohta’s idea, to give the person across from you something to do.

—There are two versions of the Slap Fight PCB; did those differences have anything to do with the development?

Yuge: No, we weren’t aware of that when developing. We only made one master program. That was probably due to circumstances with the production.


The theme for Hishouzame was a realistic depiction of war that would involve the player emotionally. We had the atmosphere of the film “Apocalypse Now” in mind. We had taken a company trip to Thailand, and we wanted to convey the mood of the scenery there in the game’s backgrounds.

We were also excited to use the new 16 bit CPU, the MC68000. We had graduated from PSG sound as well, and now were using FM sound. If there were something I could change about Hishouzame, I’d like to try making the stages longer. (Yuge)

—There were a number of significant hardware improvements for Hishouzame, but which do you feel had the biggest impact on evolving your games?

Yuge: Because we could now put more sprites onscreen, we suddenly had a lot more possibilities regarding the game system and what we could express. Whenever hardware was going to be upgraded, Toaplan would ask the opinion of the programmers, and we noted that most of our games were vertical shooters, so we chose the hardware on that premise. Having more elements on screen really opened things up for us.

—With Hishouzame, enemies now aimed their shots at the ships more accurately. How did you accomplish that?

Yuge: That was mainly a software problem, but the increased processing speed of the CPU was also related. We did tests to see whether the enemies could hit the ship at any given location on the screen. Then we were able to determine the details involving the vectors and direction of the enemy bullets. To tell the truth, the algorithms I used to determine bullet direction had some idiosyncracies. The directional cross the bullets used for aiming wasn’t done perfectly, and the angles were not exactly evenly spaced. It may be that this contributed to the game’s character, though.

—Why did you make the small boats so treacherous? (laughs)

Yuge: We didn’t want to make a game that players needed really good reflexes or hand eye coordination to clear. We wanted it to be cleared by the tricks and knowledge the player had accumulated through playing. The word “memorizer” didn’t exist then, but that’s the kind of game we were trying to develop. So the small boats are just one part of that overall goal.

—Starting with Hishouzame, you could scroll the screen horizontally by moving left and right. Was there a specific reason for adding that?

Yuge: I think we just wanted people to get more immersed in the world of the game.

—Why was the power up item “S” for Hishouzame?

Yuge: S is for SHOT. From Tatsujin on we used P, but we just weren’t thinking about it very deeply during Hishouzame. (laughs)

Kyuukyoku Tiger

Naturally, STGs are about the thrill of blowing stuff up, but we wanted a game where, just by looking at it, you could tell it would be fun to play even when you’re drunk. In fact, we enjoyed playing it drunk ourselves.

One day I was in the city and I saw some imposing tough guy pounding the Kyuukyoku Tiger cabinet with all his strength after Game Over flashed on screen. I thought we’d succeeded in make a game that people could get passionate about. (Yuge)

—How did you decide on the order the shot items would cycle through?

Yuge: We never tested other combinations. We wanted it to start with the most standard weapon, and then cycle through the progressively more complex weapons. People thought the yellow weapon was a penalty weapon, but that was just their speculation. We programmed it to be useful in cerain places, though you can also handle those parts without it if you’re properly powered up.

—Everytime you to get an item in Kyuukyoku Tiger, it makes a motion like its trying to get away from you. Was this also intentional?

Yuge: It isn’t trying to get away. It just happens to feel that way, but its definitely not programmed to move away from the player!

—When you restart after dying, and then die immediately after, you end up starting back further in the map. Why was that done?

Yuge: That was definitely in our programming, but it wasn’t an intentional feature. For programming purposes, the endpoint of the screen is actually a little bigger than the screen itself, and if you die before the screen scrolls past this section, the game thinks you’ve died in the previous section and you go back to the previous recovery point.

—At what point did you make the 2P simultaneous play version?

Yuge: It wasn’t there to begin with. 2P simultaneous games were apparently a big trend overseas, so we were requested to add it. I believe we actually did the work for it after the 1P version had been completed. Kyuukyoku Tiger had a realistic war setting, and we were conscious of the American market from the beginning. So it wasn’t out of the ordinary for us to do that.


I wanted to make a game where the more you remembered, the better you would become. I focused on adding a lot of sections where you needed a specific weapon to deal with certain attacks. One day, when I was half-asleep, I bumped my head and woke up from a dream I was having with this Laser in it… so I really wanted to add that too. (laughs)

We succeeded in bringing that laser to life, and players were surprised by it. The skull bomb Ogiwara designed was also very cool and impressive. The truth is, we were thinking about redesigning all the enemy placement for the second loop, but the idea was never realized. Its too bad. (Yuge)

—What was the reason for including speed-ups this time?

Yuge: It allowed us more latitude with setting the enemy bullet speeds.

—Were the various safespots intentionally added?

Yuge: Yes, they were. Though there were also spots that we only became aware of later.

—As much as you can remember, can you tell us what changes took place during development with setting the difficulty?

Yuge: One thing that was difficult in the beginning was that, for memorizers, there are many sections where if you initially make them too easy to learn, they become boring after you’ve memorized them.

—Ground enemies won’t fire at you if you’re within a certain proximity to them. How did this idea come about?

Yuge: We didn’t want people to think the game was unfair. If the player’s deaths weren’t satisfying, he wouldn’t want to play again.

—Starting with Tatsujin, your boards started to have features like invincibility modes and sound tests on them. Why were these left in?

Yuge: Around this time we started to do more magazine articles and game music CDs, so we thought it was convenient to leave those features in.

—Why didn’t you add a 2P cooperative mode like in Kyuukyoku Tiger?

Yuge: It was clearly against the theme of the game, and it would make the memorization meaningless. It would have really damaged the game’s character.

—There seem to be a lot of enemy designs in Tatsujin that use the human face as a motif. Was there someone at Toaplan these were based off?

Yuge: No, there wasn’t. Aside from the laser, the designs are all Naoki Ogiwara’s unique work. Maybe he used his own face? They say that since artists train by doing self-portraits, they unconsciously make other faces look like their own.


We started this game because we wanted to see if Toaplan could make a great horizontal STG, too. But it was a series of one hardship after the other, and we experienced firsthand that the “exhiliration” Toaplan always seeked in its games couldn’t be achieved in a horizontal format.

I think horizontal STG requires a different kind of appeal. You need the technical know-how for dealing with terrain, and various other different game design ideas to make it interesting. We were inexperienced with everything and it was a real struggle, but we did our best and finished it. (Uemura)

—With Hellfire, you began to put Toaplan’s name on the title screen. How did this come about?

Uemura: We were always asking Taito to let us put our name out there, but I think it was around Hellfire where Taito first recognized our “Toaplan Shooting” reputation.

—What were some of the points you struggled on with Hellfire, as your first horizontal STG?

Uemura: The system for a horizontal game, with terrain you can collide into, is fundamentally different from a vertical STG. We didn’t know how to make the game interesting, and none of our expertise from our vertical games carried over.

—In the early location tests, if you got hit by enemy bullet while you were powered up, you didn’t die, but you just powered down one level. What was the reason behind such a different system?

Uemura: I don’t remember how we finally settled on the game system, but what you describe came from trying to lower the frustration of collisions with terrain, so we tried to make the game easier with regard to enemy bullets.

—Starting with Hellfire your games had menu-based test modes. Were those modes done by your development group’s collective work?

Uemura: I think it was based on Taito’s code at first, and I remember we just added what we needed at the time.

—Which did you develop first, the 2P coop version or the 1P version? There’s a Japanese 2P version this time, but which did you intend to be the finished product?

Uemura: At Toaplan single player was always our basic focus. But there was a lot of pressure at that time to make 2P games, and decided to make Hellfire 2P from the beginning. So as far as the game system goes, we worked on both versions together.

Zero Wing

This title was created as a training project for our new hires. At that time we didn’t have any plans to release it commercially. But the decision to release it commercially made it a much more practical learning experience for the new developers, I think. On the other hand, the stage design and characters were rather cobbled together, so the world of the game was kind of a mess. (Uemura)

—Uemura, your work on Zero Wing can be seen as a continuation of your work on Hellfire, but how did you get involved with the project?

Uemura: I had been handling new hire training for awhile, and we used my work on Hellfire as teaching materials for them.

—Why did you divide the game’s soundtrack among three people?

Uemura: It wasn’t a special team or anything, we were just dividing the work up.

—You made both a 1P and 2P version, but when did each get made?

Uemura: Like Hellfire, we made both the 1P and 2P version at the same time. We planned it that way from the beginning. But, of course, the single player version represents the Toaplan style.

—In the Megadrive version opening sequence (which is especially famous overseas), was the background music made after the fact, for the port?

Uemura: I just watched this on Youtube again, and while I have certain nostalgic memories of it, I can’t remember whether I did it or not. Just listening to it, it doesn’t sound like something I did, and was probably added later. It also feels like it may have been added by someone outside Toaplan… but the atmosphere, melodies, and development of the song do feel like something I would have requested.

—The ending song in the Megadrive version is also different, but why was that done? I’d also like to know why the arcade ending song is so comical.

Uemura: Zero Wing wasn’t originally meant to be released commercially, nor was the music. It was just a simple gag, with no special meaning. As for the Megadrive version, I don’t remember, but perhaps our joking around wasn’t suitable for the port? It was probably something like that.

—In later loops enemies shoot suicide bullets, but why did you do this rather than the normal increase in speed, bullets, and enemies on screen?

Uemura: I think it was because there were sprite display limitations, so that we chose suicide bullets as our way of raising the difficulty.

—Who came up with the alien Pipiru?

Uemura: Our designer Naoki Ogiwara created him, but I don’t think he was planned in advance. He was just playing around.

—Why did you add the “warps” in Zero Wing, which hadn’t been featured since Slap Fight?

Uemura: That was also just in the spirit of play. It was a training project, and we had a lot of freedom to just fool around.

Same! Same! Same!

Our goal for Same! Same! Same!, as a sequel to Hishouzame, was to bring out the same strengths of that game. For that Toaplan thrill, we added places where you could burn everything up with the super-flashy flamethrower.

I was really pleased with the way the fire moves and sways. It came out just as I had imagined it. Things like the pallette changing desert backgrounds were designed by Shintarou Nakaoka, and I think they brought out something fresh and new. One regret I have is not being able to balance the difficulty in a way that would satisfy both game center owners and players. (Yuge)

—Why is there such a huge difference in difficulty between the 1P and 2P versions?

Yuge: There was a lot of pressure to make games that would bring in a lot of income for arcade operators. We fought about that a lot. We had to accomodate our work to this sales/business perspective, and we were forced to make a game that would, in the short term, build a lot of income. I regret it. I’m glad we were able to fix that for the Megadrive port.

—Why did you add a loop clear bonus at the ending?

Yuge: Being so difficult (even clearing one loop is a struggle), we wanted to reward the player.

—At the first location test, the name entry screen showed your progress with the loops and stages cleared. Did you think people would be playing it that long, even then?

Yuge: Yes, at the time there were many players who were competing at that level, and we were aware of them.

—Whose idea was it to include the scene with the people on the ground moving around before the ships take off?

Yuge: Our designer Nakaoka drew that as part of the background, and I said “since you’ve already done this much, let’s make them move!”

—Why do you fire off a bomb when you get hit?

Yuge: Its sort of a last bit of futility, and to make players feel unsatisfied over dying with bombs in stock.

Tatsujin Ou

I only worked on the sound for this title. As far as the coding goes, it was our first time using PCM sound, so we wanted to preserve our old style while challenging ourselves with new ideas. For the ship sound effects, I wanted to try programming them all by myself. I finished the MC6800 sound driver, and the PCM sound really expanded the limits of what I could express. So I think, as far as sound effects go, it was a great achievement for us. (Yuge)

—Please tell us about revisions and decisions concerning the difficulty level.

Yuge: I was locked in my sound room during the development, and I left the programming up to the team.

—You used both OPM and PCB sound, but what were the differences between the two? Were you satisfied with that arrangement?

Yuge: Due to certain space and memory issues with PCM, I used it mainly for drum sounds. This helped bring out the more melodic side of the FM sounds, so I was happy with it.

—The PCB hardware you were using didn’t come equipped with any sound CPUs. How did you come to use such hardware?

Yuge: The costs for using PCM had gone up. That’s why we didn’t use a z80 driver, but had to make the MC6800 driver.

—The internal music data is recorded in stereo. Was that because you expected the hardware to be capable of playing back stereo, or was it done in advance for console ports?

Yuge: I remember we tried that because we were expecting to release a Tatsujin Ou music CD.

—Do you remember any other alternate titles for Tatsujin Ou?

Yuge: I don’t clearly remember any specific titles, but we wanted to avoid things like “Tatsujin II.” We wanted to avoid numerical designations like that, because we wanted to draw people’s attention to the fact that these were new games, not mere sequels.


For this title, our goal was to make a game with the best graphics we had ever done in Toaplan (from a design, not technical, standpoint). People had pointed out that our past games were a little weak in graphics presentation. The stage 2 boss in Dogyuun is representative of our efforts; we spent a lot of time animating big bosses like that, and I think we succeeded in making something with a lot of visual impact. However, because we made graphics the top priority, the actual gameplay was kind of unimaginative. It was a shame we couldn’t balance both. (Uemura)

—In the final stage your ship becomes a giant robot, but what was the history behind that?

Uemura: Our original designs called for the protagonist to be a giant robot, but since we couldn’t make that game (laughs), we put it in the last stage as a surprise for players.

—There’s a long opening sequence in the attract mode. What was the reason you emphasized the story so much this time?

Uemura: In order to let the graphics have their full impact, it was important that the world of the game be displayed to players.

—When the 5th loop starts, the game freezes. Was this a bug you missed?

Uemura: I didn’t know about that. (laughs) There wasn’t anyone in our development team who could clear 5 loops.

—Why did you choose a game system with no power-ups, only weapon changing?

Uemura: Flashiness was the core of the game, so visually we needed the weapons to be at full power.

—When did you realize during development that there were infinite patterns that would cause the game to counterstop?

Uemura: I don’t think we knew about that.


I only worked on sound for this title, also. The team was entirely new hires, so I did teach them technical things, but I let them develop the game and code as much as possible.

The ROM space for the sound driver was extremely small (128kb), so I had to come up with workarounds in the sound driver so that the whole musical scale could be used. But we were also able to use new guitar and synth sounds, so that was good. But I really regret that we couldn’t add PCM sound to the hardware due to budget costs. (Yuge)

—Was this planned as a sequel or remake of Slap Fight?

Yuge: Several people on the development team were really into Kyuukyoku Tiger and Tatsujin before joining Toaplan, so I don’t think so.

—Was it planned to not use PCM sound and keep the costs down on the PCB production?

Yuge: We did it that way to clear out our inventory of sound chips. We resisted, and told them we couldn’t make a good game without good hardware… but in the end we had to give in, even though we didn’t want to.

—If I recall, V-V was featured on a television variety show, where people were competing for first loop clear scores. Were the developers aware of that?

Yuge: I don’t remember that scene, but we all talked about this one scene in a television drama. The actor was pretending to play during the attract mode… (embarassment)

Extra Questions

—When Toaplan went bankrupt, were there STGs you were in the middle of developing?

Uemura: We weren’t developing any STGs then. I think “Otenki Paradise” was all that remained?

—Of all Toaplan’s games, which are you personally most skilled at?

Uemura: I think Hishouzame or Kyuukyoku Tiger. Since I intentionally programmed the strategic patterns needed for each area, I know when and where enemies appear. I really did a lot of experimenting with tuning the difficulty, and I got good during that time. Of course I’m nowhere near as good as some of the players out there…

Yuge: Tatsujin. I did all the programming for it, from enemy bullet patterns to enemy placement. But… 15 years ago, when I was working at Capcom’s offices, an employee who sat behind me would sometimes bring his Tatsujin board to work. He asked me to play, and a huge crowd gathered around me, but I sadly lost all my lives at the first boss! Everyone was disappointed.

—Your sound chips evolved from PSG–>OPL–>OPM (+PCM). What kind of requests did you have for the sound as developers, and how did you decide which sound chips to use?

Uemura: The development team (that is to say, me) was always asking to use the newest music hardware, but Toaplan wanted to keep costs low. By the time we were using OPL, OPM had become the standard for everyone else.

Yuge: Toaplan produced its own hardware, so if there were chips left in stock, we had to use them all up before getting the OK to switch to new chips.

—Were you inspired or influenced by games from other companies?

Uemura: Generally, we had a tendency to follow our own inclinations, so I don’t think there was anything we were particularly influenced by. Though in the early days, I remember everyone loved Halley’s Comet (Taito, 1986) for its simplicity and excitement.

Yuge: I was very into Xevious (Namco, 1983) for its calculated enemy placement, and Star Force (Tehkan, 1984) for being fun and exciting. I think they influenced me a lot. As for game music, I loved the music of Gradius (Konami, 1985), but unfortunately I was not born with such talent in my genes, and I couldn’t make music that sounded similar.

—Regarding enemy design, was it the designers who established the way enemies would attack through their designs? Or did the programmers come up with bullet patterns and enemy toughness parameters on their own?

Uemura: In general, Toaplan very much tended to be “programmer-driven.” Though our designer Naoki Ogiwara was very vocal about his requests.

Yuge: Those things were mainly dictated by the programmers. When the designers asked us to do things for parts of the game that weren’t already preset, it was always requests like “an enemy with tons of cannons all over.”

—A relatively large number of your games have maps that are connected and continue to scroll between the levels (the screen is not wiped with a score/intermission screen). Why did you design them this way?

Uemura: When the maps are connected like that, it makes the world of the game feel more unified. Depending on the setting we didn’t always connect them, like in Dogyuun and Hellfire, where you fight in a variety of locations. It wasn’t something we had to do every game.

Yuge: For the games I programmed, I didn’t want to interrupt the player’s feeling of progress, and I wanted to preserve that tension you get from STGs.

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