The Development of Xevious

Well here we are at the end of another year on the blog. I want to thank everyone for checking in regularly and of course for the support with my book, which continues to sell well.

Over the Christmas break I found myself playing a lot of Namco’s excellent vertical shooter Xevious on my Mini Cute cabinet, and thought it would be pertinent to take a look at how the game came about.

Although licenced over here in the West by Atari, the game has a huge reputation in Japan as one which built on the success of Space Invaders, by pushing the boundaries of what a shoot em up could be. It was one of the first games to be set in a cohesive world, something built upon by later games in the genre like Darius and Gradius.

Its creator Masanobu Endo, joined Namco in 1981. Despite being a regular ‘arcade rat’ around the well known Shinjuku area of Japan, Endo-san was offered employment at the company despite having zero knowledge of game design or programming. He arrived at a time when Namco was flourishing. Both Dig Dug and Pole Position were in development and for the first few weeks, he did little else but watch and play these games as they were created and refined until release.

Inspired, Endo-san took it upon himself to gain knowledge about how to create video games:

I decided I wanted to make these games, so I started studying how to program. That was first time I seriously studied programming…then, about a month later, I started on Xevious.

Masanobu Endo

Remarkably, this one month crash course of programming led to the creation of Xevious! Namco was driven by seeing the huge success of Konami’s Scramble, and instructed its developers to design a competing game that used a joystick and two fire buttons. They used the template of their existing Galaga hardware to develop the new game. Taking inspiration from previous games, Endo’s vision was to change the core gameplay mechanic of arcade shooters up to that point:

The most popular shooting games of the time would always have the bad guys lining up at the top of the screen after they appeared. You then attacked them. But I couldn’t help but wonder why the enemies were nice enough to line up for you like that. They have to move if they want to survive, right? So that’s why all the enemies in Xevious try to escape from you — except for the unmanned ones, who you could say were made to ram into you.

Masanobu Endo

The game started out as a war themed shooter, with the player controlling a helicopter. Titled Cheyenne at this point, it took inspiration from The Vietnam war:

But during the course of its development, the game took on a sci-fi setting as the team experimented with different ideas.

Endo-san brought to the table a huge passion for all things science fiction – often clashing with his boss at the time, Toru Iwatani (the creator of Pac-Man of course) – he sought to develop a back story to the game, and took inspiration from films such as 2001: A Space Odyssey to create enemy characters. Whereas a game like Pac-Man was primitive, simple fun with no back story, Edo-san lamented the lack of depth to such games. His goal was to create a sense of mystery and immersion to the Xevious ecosystem that he believed, would engage players, ensuring repeat plays. Despite management’s objections, he stuck to his guns and was determined to see his vision for the game through.

And so Xevious tells the story of the human race up against a lost ancient civilisation that has returned to earth to reclaim the planet. The player controls Solvalou – a fighting ship used to destroy both airborne and ground level enemies and structures. It was the first vertical scrolling shooter to feature background graphics that weren’t just a simple star field.

The Solvalou is equipped with two weapons, each assigned to a button: the Zapper is used to take down airborne enemies, and the Blaster bombs ground installations utilising a targeting system that features a lock-on mechanic:

Below the Solvalou, forests, rivers and plains take shape and roll past, hinting at a South American setting, opening up to the famous Peruvian Nazca lines as the player journeys through the levels:

With Xevious, I wanted to give a video game a consistent world and setting. Within the limitations of the hardware, I wanted to create high-quality sprites, alongside a story that wouldn’t just be some tacked-on extra, but could actually stand on its own merits.

Masanobu Endo

In fact, the quality and presence of the sprites in Xevious had less to do with the hardware being able to put out a lot of colours, and more to do with the careful way the development team used different shades of grey to create the flying ships and ground installations. This was an early example of ray-tracing techniques still found in video games to this day, the style of which Endo-san was particularly taken with.

Although very much a team effort, Endo recalls how the game progressed:

Xevious was planned with a marketing perspective: we thought a scrolling, two-button game would be a hit. In that sense, it began as a very standard game in which we were trying to follow the market. The goal, then, wasn’t to program a super-difficult game, but rather something that would be ok for new players too. I worked with a senior colleague who became my teacher, and he had me do a wide variety of tasks: he had created the basic shape and “bones” of the game, and I went about fleshing everything out.

Masanobu Endo

Xevious features one of the first examples of a ‘Boss’ enemy. The ‘Andor Genesis’ is a huge flying fortress that appears four times in the game:

All rendered in the aforementioned shades of grey, each airborne enemy has its own behavioural traits. Some simply float (like the rotating monoliths) and can’t be destroyed, only avoided. Others rotated, then retreated if left un-shot. Some evade the player by flying off to the sides, or fly northwards off the screen after making a brief salvo to attack the Solvalou. Each look distinctly like something that could come from outer space. It would have been possible to render each enemy in a different colour (as in many post-Galaxian shooters), but the overall impact would have been far less striking.

The ground-based enemies generally are less of a threat. Many are static and don’t attack the player at all, whilst others do move across the terrain and take pop shots as the player passes over them:

Perhaps the most innovative and striking feature of Xevious is its level design. The scrolling background is actually made up of one large 1024×2048 image map:

Each of the 16 game areas is in fact a 224×2048 strip starting at a different horizontal point at the foot of the larger image above:

If you’re interested, some of the original development notes can be found here.

Each slice of the bigger map is mapped out as a ‘level’ below:

The areas are separated by a green forested section, although there is no distinct indication of a change from one to the next. Each time a life has been lost, if 70% of that area has been completed, the player’s ship starts at the beginning of the next, rather than back to the beginning.

An interesting footnote to the core mechanic of the game is that there are plenty of secrets hidden within the Xevious world:

As you play, you may notice that the lock target crosshair turns red even if there is no enemy shown. This indicates the position of a hidden ‘Sol’ tower below the ground surface. Bombing these spots reveals the tower and earns the player 2000 points, destroying it once revealed, will earn a further 2000 points.

We ended up adding a target for when you fire at ground enemies. I had three colours to work with on the target. It occurred to me that I could use those colours to make it flash. I then coded it so that touching an enemy with the target would make it flash, as a sort of way to tell the player “fire!”. Then I got to thinking: what if I made it flash, telling players to fire, but there was no enemy visible…? That was how I came up with the idea for the invisible Sol enemies. This hidden stuff really pissed off Namco!

Masanobu Endo

In addition, Special Flags (using the same sprite found in Namco’s Rally X) are hidden throughout the game. These are much harder to find, as there are no clues to their whereabouts. Revealing one with a bomb rewards the player with 1000 points and collecting it awards an extra life or 10,000 points, dependent on the boards settings. For the curious among you, the sliced map above shows the location of the flags, although they are randomly placed horizontally across the screen – so whilst you might be able to memorise the location, some randomness and luck is required to collect them.

A message from the programmer ‘NAMCO ORIGINAL – program by EVEZOO’ can also be viewed by dropping to the bottom right of the screen as soon as you start a game and mashing the bomb button. A generous 10 points is earned by doing this! This feature is actually an anti-piracy device: Bootleg boards will display a different message when doing the same thing: ‘DEAD COPY MAKING – copy under NAMCO program’

The placement of these easter eggs have added to the mystique of Xevious, drawing players back time and again in an attempt to reveal the game’s secrets – a deliberate inclusion by Endo-san and his team. Alongside the back story, which I won’t go into, but you can read it here, Xevious became more than the sum of its parts, and its Japanese audience lapped it up. A long defunct webpage detailing the hidden secrets of Xevious can be found here.

After one month of testing in December 1982, Xevious was released in Japan during January 1983 to wide acclaim. It recorded record-breaking cabinet sales that had not been seen since Space Invaders in 1978, and in November 1983 it was the top-grossing table arcade cabinet according to trade publication Game Machine.

It is believed that the game was released only in table top form in Japan, although a bit of digging around does reveal a Xevious upright cabinet did exist, albeit in small numbers. Click this image to be taken to a bizarre video featuring several Namco upright Japanese cabinets, including a Xevious!

The game was quickly snapped up under licence by Atari in the USA, and they gave it the full artwork treatment, producing what must be one of the most gloriously well-worked arcade cabinets of the golden age of video gaming:

As well as design, Atari went full bore on the marketing effort, with colourful flyers and this fantastic promotional video for operators:

Here’s a cool picture: Masanobu Endo himself visited the Atari factory in California to witness the build of the cabinets over there:

And another worth sharing. Here’s the original mock up sketch of the Atari Xevious bezel created by Mike Jang for the art department:

So that’s Xevious – a great shooter well worthy of your time. It set the standard for future vertical shoot-em-ups that followed. Do check it out if you can find an original cabinet, or fire it up on MAME where it is fully emulated.

So with all that said, I’m going to get back to my Mini Cute and up my high score!

Thanks as always for reading this week – please consider giving this article a share if you feel inclined.

See you next year!

Tony

In memory of Mike Stulir, Vice President of ACAM.