Gradius Gaiden – Gradius Portable Guidebook Interview

Isobe Keiichi (En’you Ryou): Player ship design, programming for stages 4/7 enemies, Stage 4/6/7 bosses, Triple Core, Heavy Ducker, and others. Also oversaw art design for the instruction booklet. His other works include the Gradius Deluxe Pack and OZ.

Kobayashi Takayuki: Game system design, programming for stage 1/2/3 enemies, stage 1/2 bosses, Laser Tetran, Neo Big Core, Sol, Heaven’s Gate, and others. His other works include Suikoden IV and Rhapsody.

Chigasaki Kei: Backgrounds, game system design, programming for stages 3/5 bosses, Juggler Core and others. His other works include Gradius Deluxe Pack and Tokimeki Memorial.

Yamazaki Yukihiro: Programming for stage 6 enemies, Metal Serpent, DeathDouble, Deltatry, Boost Core, Gunner Wall, and O.V.U.M. His work includes the Dance Dance Revolution series and others.

Miura Norikazu (Nories Miura): Sound Composer. Worked on stage sound design. His works include Bugi, the Winning Eleven series, and more.

Stage 1: Beyond the White Snowstorm

Kobayashi: We decided to make the first stage something fresh, so we choose a snow stage, which was new for Gradius. In the second loop the snow pushes the player’s ship downwards. Some of us were saying that should be in the first loop, actually.

Isobe: But of course it turned out to be too difficult that way, so we left it out. Even so, people who see the snow for the first time always get really nervous: “can that hit me?!” (laughs) So I think we achieved our goal of surprising people.


Snow stage concept art.

Stage 2: Requiem for Revengers

Kobayashi: The idea for a graveyard started from asking how we could bring back older characters and bosses from the series as a bit of fanservice.

Isobe: We were talking about how to present them in an interesting way when someone said, “Well, aren’t they all destroyed now?” (laughs) In a sense, this stage is a kind of “farewell” to them all. (everyone laughs)

Kobayashi: The forking path ended up being featured only in this stage, but we actually wanted to do that in other stages, too.

Isobe: The boss for the lower path is named “Noobiru” [[Nobil]] because his tentacles extend. (everyone laughs) “That’s your idea of a pun?!”, they said. I cracked up. 1

Yamazaki: During development, his arm extended incredibly quickly. It was crazy.

Isobe: Yeah, with bosses, they’re definitely at their strongest right after you’ve created them. (laughs) While you’re making them you just keep thinking “I’ve got to make him stronger, stronger, stronger!” Then everyone plays it, and it becomes “how can I make this easier?”

Kobayashi: When you add all these different attacks and detailed movement patterns, bosses naturally are quite strong at first. Then you have to find the right difficulty balance for them.


Stage 2 concept art.

Stage 3: Into the Crystal Cage

Isobe: I put forward the idea for this stage, and I made it, but… I think I tied a noose around my own neck in doing so. (laughs) The way the lasers reflected was extremely difficult to make because I had to consider the placement of all the enemies and the player’s ship as well. But I think it was worth the trouble, because it turned out to be a very impressive stage.

Yamazaki: At first we placed the enemies so they would be difficult to hit with the reflecting laser, but when we actually playtested it, it wasn’t very fun. So we went in the opposite direction and placed them so they’d be easier to hit with the reflecting laser.

Stage 4: Ruins of Silence

Isobe: After Gradius Gaiden had been released, I looked at the player feedback survey cards and saw so many responses that said “I died on the 4th stage.” It seems this is the stage where people think the difficulty suddenly shoots up.

Yamazaki: The idea to have the Moai heads break in half and fall off came from the Playstation hardware’s rotation effects, which were now easier to use. I think the combination with that and the laser eyes made for a fun and interesting design. If you shoot them right when they’re shooting their lasers, you won’t know which way the head will roll, so its wickedly difficult. (laughs)

Isobe: For the laser Moai, we were pretty much out of new ideas for the Moai. Then someone said, “Well, what if their eyes shoot laser beams?” (everyone laughs) They said it as a joke, but we ended up going with it! The boss, Moai Dimension, also came from PS rotation abilities. “We can do rotation so easily, so let’s try and make everything spin!” (laughs)

Yamazaki: With the PSX you could do sprite rotation, scaling, and really anything related to size–lengthening sprites, enlarging them, shrinking them, etc. So it was a natural fit.

Isobe: The name came from the idea that you were in a space surrounded and enclosed by Moai, aka the “Moai Dimension.” (laughs) We also added a lot more speech for the boss this time.


Crystal Cage stage concept art.

Stage 5: Organic Fortress

Kobayashi: Chigasaki’s background work really shines here with the way the walls undulate up and down.

Chigasaki: Using the PSX’s processing speed, I experimented with a slightly different method with the VRAM for that terrain effect.

Isobe: Looking at Gradius Gaiden as a whole, we tended to spend a lot of time trying out new terrain ideas. When I later saw the magma stage from Gradius IV, it occurred to me that maybe we were inspired by it.

Yamazaki: The boss Mad Skin is, in a certain sense, the strongest boss. (laughs)

Chigasaki: Maybe so, in the sense that you can’t just memorize and reduce his attacks to a pattern.

Isobe: I often get hit by those gum balls and die. (laughs)

Chigasaki: Since you can’t ultimately predict the angle at which the balls will bounce off, dodging this isn’t about memorizing a pattern, but rather about kiai. 2 I know that’s a taboo word… (laughs)

Stage 6: Green Inferno

Yamazaki: The idea for enemies that come from behind in the very beginning was taken from the MSX Gradius 2. (everyone laughs)

Isobe: Yeah, the green plant stage itself was first in MSX Gradius 2, also. (laughs)

Yamazaki: Yeah, Gradius Gaiden is full of homages to past Gradius games. The weapons having two levels to power-up is also from the MSX versions.

Kobayashi: Yamazaki, you made this stage, right?

Yamazaki: Yeah, though as you can see, its really just a cobbling together of other people’s ideas. (everyone laughs) I don’t even remember how many enemies I created for it. Actually, for the walker enemy, I made both a 2-legged version and a 3-legged version. In the end I had to cut the 3-legged version though.

Isobe: I made the boss for this stage, but it was frustrating how our concept for the boss kept changing. I remember he first went through 3 separate transformations. By the way, his third attack that sucks you in came from the Gradius III plant boss (Choking Weed).


Black hole and Moai stage concept art.

Stage 7: On the Event Horizon

Isobe: This stage is my personal favorite. Early in the development we asked “What shall we do for a volcano stage this time?”, and people were like “I guess we have to put one in, its Gradius after all.” (laughs) We thought of doing the usual volcanic eruptions, but since this was the PSX, we definitely wanted to revise it with some kind of background or terrain effect.

Yamazaki: Ahh, I love this stage too. Its cool how the music really matches the stage.

Isobe: We made it so only the player ship’s missile is affected by the gravity. Some were saying the standard shot should also be affected, but it was like, “then there won’t be a game to play!” (everyone laughs) The enemy shots do curve, but lasers are unaffected. That little detail was a nod to our love for sci-fi. (laughs)

Stage 8: Formidable Guardians

Yamazaki: This is an all original boss rush. We felt, and so did the director, that just rehashing all the prior bosses would be boring, so we reworked it a bit.

Kobayashi: Yeah, and all those bosses were buried in stage 2 anyway. (laughs)

Isobe: DeltaTri was inspired by Trigon. Both the director and Yamazaki, who made that boss, were fans of Trigon. Though personally, when I think “dragon laser”, I think of Gaiapolis. (laughs)

Yamazaki: At the end when he self-destructs by turning his dragon lasers on himself, that was meant to show the gallant heart of the samurai: “I will not die at your hands!” (laughs) By the way, in the second loop, you’ll notice that destroying the dragon lasers sometimes causes a lot of suicide bullets to come out, and sometimes only one… that was an object overflow problem. (everyone laughs) When he spits out the scattered bullet pattern before, I ran out of allottable objects for the suicide bullets. Also, I originally thought this name was really cool, but now that I think of it “delta” and “tri” both mean triangle… damnit! (everyone laughs) Well, this was an homage to Trigon, so I definitely needed to have “Tri” in there somewhere.

Isobe: By the way, the music after DeltaTri changes because we wanted to signify that you were entering the latter half of the boss rush. Our nickname for it was “bosu bayashi” 3 (laughs).

Stage 9: Fate…

Yamazaki: The way the BGM syncronizes with the start of this stage is so cool. Miura, who was in charge of the music, synced it up for us precisely with the start of the stage.

Isobe: The previous high speed stages in the Gradius series had a lot of starting and stopping, and some felt this took away from the sense of speed. So we removed those as much as possible. Racing through the successive shutters at the end is a cherished Gradius tradition we had to keep in, though. (laughs)

Yamazaki: Now that time has passed, I can say this, but… the Gunner Wall was inspired by the boss of a certain arcade game that I was obsessed with at the time. 4 I’m sorry. (laughs) Especially when comes at you and traps you with the needle bullet pattern.

Isobe: Well, for Gradius, that kind of bullet pattern was something fresh. I also really like the flashy explosion when this guys dies. Yamazaki, you sure put a lot of care into the way your bosses exploded. (laughs)

Yamazaki: Yes, I love explosions. (laughs) I really like the flashy explosions in AJAX. But the truth is, the graphic patterns we had for explosions in Gaiden were rather small, so it was a struggle.

Isobe: The next boss, Heavy Ducker, was created by me. Making his roller dash and the way he attacks from the background was simply my little pet project. (laughs)

Yamazaki: The earlier version of Heavy Ducker was a real bastard! For the attack where he drops mines that shoot pillars of fire, there were many more mines, and it was practically impossible to dodge on sight. (laughs) Though if you observed the timing really closely, you could somehow manage…

Isobe: Even I didn’t feel like I could clear that attack. (laughs) The next boss, Sol, was nicknamed Uni. (laughs) Here too, we knew we wanted to pay homage to Crab from Gradius II, but this particular design wasn’t decided on till very late. Finally we ended up using the PSX’s rotation effects.

Yamazaki: Kobayashi made Sol, and I was impressed as usual with how quickly and effortlessly you completed him. I’m really bad at creating those fine, smooth movements.

Kobayashi: No no, that’s not true. (laughs) The director had a lot of ideas for this part, so it was easy to make.

Yamazaki: Kobayashi likes to make spinny bosses. (laughs) Laser Tetran was like that too.


More stage concept art.

Final Boss: O.V.U.M

Isobe: The last boss, who seems to want to tell you something. (laughs) Man, we were wracking our brains over what do for him up to the very end. His name is meant to be read “Obamu.” In English, I believe it means “abnormal shape.” 5 “The Original Visions of Ultimate Monster” was added later.

Yamazaki: We struggled with him a lot–truly befitting the “last boss.” (everyone laughs) The presentation was very abstract, and half of him was just a bunch of sparkling lights.

Isobe: The basic idea was for him to be like an illusion, an existence without a clearly discernible body. As for why he takes the appearance of Salamander bosses, well… our image was of “spirits” that would appear one after the other without much rhyme or reason, and the Salamander bosses were easy to use.

Yamazaki: The small sphere that appears at the very end is his true shape.


Yamazaki: The staff roll is in Japanese. And the font is large! (laughs)

Isobe: I can’t help but laugh everytime I see it. (everyone laughs) Why did we decide on kanji for the credits? Its different, but something seems off about it… well, either way, its easy to read! Its good for we Japanese. (everyone laughs)

Kobayashi: I also like the ending song.

Isobe: Yeah, it exudes feelings of liberation and relief… “Ah, my work is done!”

The Gradius Gaiden development

Isobe: The development period was just under a year. We really strived to create a fun, balanced game–not just as an addition to the Gradius series, but as a STG game also.

Chigasaki: The Gaiden staff originally worked on the Gradius Deluxe Pack. So everyone was very knowledgeable about Gradius, and while we were porting the arcade games, there were a lot of strong opinions exchanged about how “I would have done this differently!” and such. (laughs)

Yamazaki: And of course we were very conscious of the fact that this was a console game we were developing. We added more power-up capsules than normal, and made the checkpoint recovery easier than the arcade titles.

Isobe: Unlike an arcade game, you don’t need to use up a bunch of quarters to play. We didn’t have to follow a “kill the player in the 2nd stage!” arcade philosophy (laughs), and we could pace the difficulty in a more balanced way, with the goal of progressively raising the player’s skills.

The Origin of Gaiden

Isobe: We decided on the Gaiden title first, and the story came later. So to be honest, we didn’t really think too hard about the story connections with the Bacterian empire and so forth. But that said, we did feel that by using older characters, the bosses’ wrecked shells, and other references, that connections would be suggested to the player, while leaving the details vague.

Chigasaki: The truth is that, at first, our team really wanted to make an official numbered entry in the Gradius series.

Isobe: But it actually turned out that doing a Gaiden entry, we could come up with ideas more freely. I think in the end it was very advantageous.

Yamazaki: And by calling it Gaiden, we could avoid the potentially severe critcism from core fans. “Gaiden? You mean its not part of the official series? Ah, but its still so fun!” (laughs)

New Ships

Isobe: I remember there was a conversation in the beginning about how it was kind of sad that in previous games when the ship changed weapons, its appearance didn’t change.

Chigasaki: At the start of development Gaiden was 1 player only, but along the way we added 2P simultaneous play. So for 2 player games, we needed a way to visually differentiate the ships.

Isobe: That brought up the different looking Vic Viper and Lord British from Salamander, but since we had 4 types, we needed to design two more ships.


Black hole and Moai stage concept art.

Yamazaki: Everyone contributed ideas for the ship names and weapons, and we decided on it freely amongst ourselves.

Isobe: By the way, regarding the Falchion β… after we completed Gradius Gaiden, I learned of the existence of the FDS game Falsion. (laughs) The similar names are a complete coincidence.

Yamazaki: What, really?! This is the first time I’ve heard that. (laughs)

Isobe: Its true. I thought “Falchion” alone was a little too short for the name of a ship and didn’t quite fit, so to give it some weight I added the “β.” Then, later I created the story that “actually, there was an alpha version of the Falchion…”, and people were like “Whoa, that’s cool!” (everyone laughs)

New Weapons

Isobe: The hardest to make was the disruptor. It was way too strong at first, but when we tried to balance it we made it too weak. (laughs) As a result I think the Lord British ended up being the least rewarding ship to play.

Yamazaki: Yeah, but a lot of people like the ripple laser. (laughs)

Isobe: Its true, Gaiden’s ripple laser takes the place of Double. It felt like Double wasn’t very well received as the Gradius series went on, so we decided to try to improve on it.

Yamazaki: The Vic Viper double that can shoot behind is very powerful.

Isobe: Also, the Falchion β Auto-Aiming weapon was my idea. It came from my own bitter experiences, where I’d aim at something but then an enemy would get in the way. I thought, “theres never been a homing weapon in Gradius that doesn’t require you to be horizontally aligned with the enemy, has there?” (laughs) During development there was no limit on the fire rate, though, and it was too strong so we scaled it back.

New Barriers

Isobe: Since we’d gone to the trouble of making 4 ships, we felt we might as well make 4 different barriers. The idea for “guard” came from me being bad at Gradius games and always dying when I hit the walls. So I right away I demanded a barrier for the terrain. (everyone laughs) Limit came from the idea of making a barrier that was about time rather than durability.

Gauge Edit

Isobe: This was an evolution of the edit mode in Gradius III. “Since we can change the weapons (vertical), why not allow players to change the order (horizontal)?” When we actually tried it out, it was surprisingly fun. (laughs) You know, in Life Force the Lord British ship had a different power-up order. Since they had done it there, I figured it would work out here.


“Requiem for Revengers” stage design rough draft.

Second Loop

Isobe: We thought that just increasing the enemies and making them tougher would be boring. (laughs) We tried changing the enemy algorithms and increasing their number. It was simply fan service. Also, there were things we regretted removing from the game that we were able to bring back under the guise of a second loop.

Yamazaki: I was part of the “A Stronger Second Loop!” faction. (everyone laughs) I remember someone yelling out at a meeting, “We HAVE to make the second loop more difficult!” Arcade STGs of the time had two loops, and the second loop was always incredibly difficult. I definitely think that inspired us, well, for me personally at least. (everyone laughs) I liked the idea that players would feel like the second loop was an invitation to a deadly contest!

Chigasaki: Heaven’s Gate was made specifically for the second loop. We ended up having some free time in our development schedule, and I think Kobayashi made him. (laughs)

Yamazaki: Heaven’s Gate actually has a safe spot, and we knew about it before the game was released. (laughs)

Kobayashi: But if you just fight him normally, he isn’t that hard. He reveals all his tricks after you fight him once. Just by staying in the middle you should be able to dodge his attacks, and its very easy.

Isobe: The prelude Kuchuusen melody also changes for the second loop. Originally the composers made two version of Kuchuusen for us, but we all thought the Sky #2 song was better. Though later some people told us it doesn’t seem to fit the Gradius series.

Ideas that didn’t make it

Isobe: At the idea stage we had the image of a “Sea of Mud.” The terrain would be like the Bubble stage from Gradius III, but the ship’s movement would be slowed down. But someone said, “would this even be fun?” (everyone laughs), and that was the end of that idea.

Kobayashi: We also thought of having a Crab type boss in the last stage who raise the walls as he walked.

Isobe: Really, we didn’t abandon many of our ideas. Almost everything we thought of in the beginning made it in.

Chigasaki: But we did change the order of the stages around two or three times. During the development the internal organ stage was 2nd, and the graveyard stage was 7th. But in terms of color the graveyard and base stages were too similar, so we separated them. We did a lot of changes like that.

Isobe: Also, the high speed stage was stage 6 at first, and separate from the final base stage. We joined them together later. We thought it was cooler if it felt like you descended into the final boss’ lair, so we put them together.

Yamazaki: I think it turned out to be a really cool final stage because of that.

2 Player Simultaneous

Isobe: The first thing we stumbled over was how to divide the 4 options between 2 players. At first we made it that whoever got them first kept them, but that way the more experienced player always won. So someone suggested being able to exchange the options. (everyone laughs) It ended up being like a pseudo-competitive system. (laughs)

Yamazaki: You know, I thought it was great. It feels almost like a minigame, but its a good system.

Stage Titles

Isobe: I was allowed to name these. (laughs) Every Gradius game, the stages have rather plan names. Just “Volcano” and so forth. At that time a lot of arcade STGs were using fairy tale like settings. I thought that was really cool, so I tried to add something like it to Gaiden. I’m not sure I was successful for every stage though. The black hole stage name “On the Event Horizon” came very easily, since I love science fiction. (laughs)

The Sound of Gradius Gaiden

Miura: At the start, the director told me he wanted me to approach the sound in a way that was distinct from all previous Gradius games. Since the playback method was different from arcade games (the PSX used CDXA sound format), I tried to do things that could only be done on a console system. I wanted to make full use of the advantages of a console port, and I tried out various compositional approaches to that end. I think I really had a lot of freedom in writing the music for Gaiden.

The main theme, Sky #2?

Miura: Officially we never announced a main theme for Gaiden, but Sky #2 was it. It uses the same melodic phrase as SPEED. Originally it was used as the Jade Knight’s theme, but we wanted a unique melody to represent Gradius Gaiden–something that you hadn’t heard before in the Gradius series–and Sky #2 fit that role. It also features prominently in the original soundtrack as a bonus track.


Enemy sketches.

Looking back on Gradius Gaiden

Isobe: Of all the titles I’ve worked on at Konami, this is the one I have the most confidence in. I tell people this work represents my heart and soul.

Everyone: Ahhh!

Isobe: I was so lucky to be given this project. I learned a lot from it, and it was the first time I made a game that I myself enjoyed playing. During the development I was really into scoring, too. (laughs)

Yamazaki: It was really fun to create. It was fun to make, and fun to play… it felt like, “should I be getting paid for this?” (laughs)

Isobe: Yeah… that’s the ideal game.

Kobayashi: For me, Gradius was a game I had played a ton as a kid, so in that respect the pressure was immense. Even so, I was so grateful and happy to be able to create a new Gradius title.

Chigasaki: Gradius is such an emblematic title in the world of STG, so I too had a lot of anxiety at the time about creating a new entry in the series. But in the end, unlike the Deluxe Pack we were able to fully utilize the abilities of the PSX, and the game is still rated highly by fans, so I’m glad I got the chance to work on it.

Yamazaki: I joined in the middle of the development, but to be involved in a Gradius game was like a dream come true to me. I was so happy. I joined the game industry because I wanted to make STGs, so to suddenly be working on Gradius made me incredibly happy. In many different ways it was a memorable project for me. It was the first time I felt the actual sensation that “this is how games are made!” Looking back on it, being able to come up with ideas and try them out then and there was a development style that you don’t see very often nowadays.

Isobe: It was like doing a live show.

Yamazaki: If we thought something was fun we’d just add it, and more and more new ideas got added everyday. It really felt like “this is how you make a good game.”

Isobe: Its partly thanks to our director, who wasn’t afraid of adventure.

Kobayashi: He was always saying we needed to take on new challenges.

Yamazaki: That’s right. He’s an extremely prideful person who hates to lose. “I won’t do anything that’s been done before!” is what he used to say. I think that kind of attitude has a lot to do with creating an original game. I’d love to work on a development project like this again… I want to make a new Gradius game, with this staff! Of course it wouldn’t be Gradius VI, but rather Gradius Gaiden 2. (everyone laughs)

Isobe: For those who encounter Gradius Gaiden for the first time on PSP, I hope you don’t take the Gaiden title in a negative way. It does many things the main series can’t do, in a good sense. Please enjoy it for what it is.