Q&A: Rayman Advance

A Q&A session was held recently with Yannis Mallat, project manager of Rayman Advance for the Game Boy Advance. Mallat spoke about the game's development and specific features, and he also described some of the challenges involved in developing a game for the GBA. Rayman Advance is based on the original Rayman platforming game, which was first released on the Atari Jaguar and then ported to the Sony PlayStation in late 1995. The entire Q&A follows.

Q: How long did the development last, and how many people worked on the game?

Yannis Mallat: Development time was close to one year, with a full-time team of 30 and others helping out as needed.

Q: How did you go about developing a game for a new handheld console?

YM: We had to build from scratch and create a library of tools while we created the game, which wasn't easy.

The team employed several compression techniques. As you can see in some of the boss characters, they appear to be a little bit stockier than the other characters. This is because they are smaller sprites that use the GBA's hardware scaling. They are stored as much smaller objects, which then take up less room, but they're displayed to proper scale via the hardware. Also, the backgrounds are created in standard tile format of 8x8 squares and assembled like a giant jigsaw puzzle. The artists and level designers have about 800 tiles to choose from, and they mix and match them to build the levels. In that game, you can see that the levels are made up of boxes. What the Rayman team had established originally, and what the new team has continued to do, is create seamless tiles--that is, tiles that do not look like boxes but rather look more organic, as if the game were not made up of tiles. This, of course, is extremely difficult to do under the limitations. Had the levels been streamed with entirely unique tiles, the game would have been easily 512Mb or more. What it boils down to is an artist who has a career's worth of work under these limits and can generate hundreds of interchangeable tiles, seamless to the naked eye.

The programmers on Rayman deserve a lot of credit for forging the way. They were able to take many of the original assets and create tools and the process to convert art, animation, and game logic from the original Rayman to the GBA.

The GBA can accomplish amazing feats visually, but it comes with a price. It still has a way to go before we can do anything as freely as you would on a higher-end console or PC.

Rayman, like the original, is made up of separate sprites, which is why his hands and feet float without any means of connection to the body. This saves a lot of graphic space, because the sprite bitmaps are fewer in number, and they're traditionally quite large. Had we stored Rayman frame by frame, his entire body, he would have required nearly 20 times the cart space, or more. Instead, we store only coordinates and sprite reference numbers. This gives major savings on ROM. Because the sprites need to load data nearly every game frame, they need to minimize color usage. The reason is, the more color depth, the more data must be transferred. Originally, all sprites were going to pull their colors from a shared palette of 256 colors. That is how the PC version of Rayman was built. Similarly, the PlayStation version used a large number of colors. This was fine, but the ROM footprint for sprites using that many colors is much larger and requires more time to transfer, especially on the Game Boy Advance. It dropped the frame rate to about 15-30 frames per second. The solution was to bring the sprites down to 16 palettes of 16 colors. This was difficult, because before that, the sprites shared a large common palette. Again, the artists had to redraw all the sprites and wisely select color palettes. The amount of work paid off, as the result looked nearly identical to the revision before it, and we accelerated the game to acceptable speeds.

The artists have done an amazing job bringing the original lush graphics to the GBA, and they worked successfully to achieve such a high level of quality with such a limited palette of color.

The GBA has so many limitations, and sound is one of the biggest. In order to sustain the amount of processing for the visuals and the game logic, it left very little processing for music.

Q: How did you succeed in taking advantage of the console's maximum capacities?

YM: Up until the last few months of the project, the game was nearly twice as big as it was when it finally shipped. We then had to focus on compression for a 64 MB cartridge. The first thing people will notice is the large amount of color and animation the game has, as well as how big some of the game characters actually are. Some of the boss characters are as large as the screen itself! This is done only because the GBA has the power to do it. Also, the sheer number of active elements on the screen, being animated and moved, is a testament to the power of the GBA.

Q: How did you work on the graphics and animation process on the Game Boy Advance?

YM: We had to create several tools and animation software, along with good-old fashioned pixel pushing, to pull off all the visuals you see in the game. First, we needed to create a tool that would take levels and regenerate them as Game Boy Advance-compliant data. The result was excellent, but it still needed a lot of work from the artists. We also needed a sprite manager. This came a little bit later in the project, as the lead programmer already found a way to interpret the PlayStation animation data. The sprite tool was then applied to the remaining elements of the game that had to be created from the ground up, such as the interface and introduction sequence.

Q: What are the main challenges one has to cope with when developing a game for the GBA?

YM: One of the major challenges is trying to fit so much gameplay, artwork, and sound into a cartridge with such a small capacity. On consoles, you can rely mostly on CD or DVD for storage. The GBA offers no such luxury. Of course, we had serious problems sometimes. For instance, we had been pretty happy until we finally received the street model of the GBA. The screen actually displayed the game much darker than on our development units. So the art team had to go back and rework all of the color for the game. It was a crazy time, as the game was nearly ready for manufacturing. Such is the cost of being first on a system.

Q: The color palette in Rayman Advance is particularly impressive. Can you talk about that specifically?

YM: As for the color, a lot of credit goes to the original game designers. Where the GBA team shines is in the down-sampling of all that color. There really was no easy way to do this other than to whittle down the palette and redraw the art several times until we reached the target palette. It literally was a process of revise, test, modify, and so on.

Q: Thanks for your time.