3 D Sonic Devs

Just last week we shared details from an interview with M2 President Naoki Horii and SEGA CS3 Yosuke Okunari that revealed some of the challenges in producing 3D Space Harrier, making it clear that producing a 3D remaster of the arcade classic wasn't a simple process. With 3D Sonic the Hedgehog arriving in Europe and North America this week, a follow up interview originally conducted by Impress Watch (and translated by Siliconera) has now been released to cover the process of that release.

Unlike both 3D Space Harrier and 3D Super Hang-On, which were both based on arcades, this week's Sonic entry attempts to apply the 3D magic to a Mega Drive / Genesis title. The challenges were substantial for that due to multiple reasons; turning a 2D game into an enjoyable 3D experience is an issue in itself (unlike the aforementioned arcade titles that both had 3D camera perspectives), while on a technical level there were problems running a Mega Drive emulator on the 3DS.

In order to get around these problems the M2 team did something rather impressive — it created a new "virtual" console. In many senses it's actually an all-new system, except of course for the fact that it currently only exists in emulated form; with that said it could in theory be built and be a real console, with the team labelling it as a GigaDrive.

NH: From M2’s standpoint, since we’ve gotten away from the original plan to emulate the game in 3D, and instead wound up creating an extension of the hardware spec that makes it easier to put MegaDrive games into 3D, we think of the GigaDrive as an ‘unofficial’ new SEGA console.

The specs are very clearly defined, and someone out there with enough skill could make probably make the same hardware. That’s the level at which we’ve built it. In other words, if you (virtually) popped in a GigaDrive cartridge, you could play Sonic in 3D, and if you took an old MegaDrive cartridge and put it in, you could play that too; we’ve built it with that type of cross compatibility in mind.

Personally, this is something I care deeply about. I don’t know how people would react when they hear the word “GigaDrive”, I don’t know if they’d say “Huh? …what’s that?” or get totally hyped about it, but I’ll send you a spec sheet, so you can check it out for yourself. (laughs)

Elsewhere in this interview, it was explained in detail how the Sonic Dash was added to the game; originally the move made its début in Sonic the Hedgehog 2.

YO: We’ve made the stage select a standard feature because we want players to see every stage, and for the people who gave up on the original to come back and give Sonic another try. One more thing is the Spin Dash. This was actually a lot of work to put in. These days, everyone knows the Spin Dash from modern Sonic, but it wasn’t in the very first game. So when people go to play the first game, they’re like, “Wait, what?” (laughs)They always try to Spin Dash right away.

...YO: Yeah, after M2 worked so hard to get the move in, they told me they wanted to make the Spin Dash the game’s “Special” feature. But I said, “No no no, in this day and age, people expect the Spin Dash. We should just slip this into the main game.” No one’s likely to turn off Spin Dash, other than those who just really want to play the complete original version. Not nowadays. So we quietly included the option to turn Spin Dash off in the back of the system options.

NH: And I was fine with that… Okunari-san always comes to us with these sorts of proposals, and we’re more than happy to implement them. But then… when we tell him, “Hey, um, you know this is going to take a while, right?” and start talking deadlines, he’ll tell us: “The deadline is iron-clad. If it’s not going to make it in time, then we don’t have to implement it.” That’s the spiel, but somehow every time, the changes make their way in…. Okunari-san has a lot of opinions that come from him personally, and not from a producer perspective. And I think that’s without a doubt been key in maintaining the quality of the 3D Remaster Project.

As always, we recommend reading the full article, which contains a lot of terrific detail on the development processes and extra features included with the game. For those of you that love the idea of a GigaDrive, below are the specifications that can help make the hardware a reality.

GigaDrive (aka Super MegaDrive) Specs, Draft v1.0.

In a fictional version of the early 1990s where 3D TVs have proliferated, M2 has finalized the specs for an imaginary 3D TV-compatible SEGA game console, the GigaDrive. The 3D MegaDrive, which will subsequently be released by SEGA, will conform to these imaginary hardware specs. While highly unlikely to ever see the light of day, in the off chance that it does, M2 has taken careful consideration to ensure backwards compatibility with MegaDrive cartridges. In this era, once 3D MegaDrive titles popped up, a fair selection of games were released for the GigaDrive.

Hey you!! Why not give SEGA’s new imaginary console a test drive with 3D Sonic?

  • Please note the specs below are in draft form. There will be changes in subsequent revisions.

■ The GigaDrive supports backward compatibility with MegaDrive games (Unmodified MDROMs will run normally without modification)

・Expanded VDP register for controlling expanded functionality included

・Expanded VRAM included

・Four extra background layers included

・Z-values can be set for each extra background or raster line

・Every sprite has a Z-value setting.

・VDP and Expanded VDP registers are memory-mapped and accessible

・VRAM and Expanded VRAM are memory-mapped and accessible


  • Memory Map
  • $c00000 r/w VDP DATA
  • $c00002 r/w VDP DATA
  • $c00004 r/w VDP STATUS(read)/CTRL(write)
  • $c00006 r/w VDP STATUS(read)/CTRL(write)
  • $c00100-$c0012f -/w VDP REGS(write only)
  • $c00130-$c0015f -/w EXT VDP REGS(write only)
  • $c00200-$c0024f r/w VSRAM
  • $c00300-$c0030f r/w DIPSW
  • $d00000-$d0ffff r/w 64KB VRAM
  • $d10000-$d1ffff r/w 64KB EXT VRAM

――Detailed I/O Map spec omitted――

[source siliconera.com, via game.watch.impress.co.jp]