i-mode phones2005Japan onlySonic TeamKart racing

Sonic Kart 3DX (2005)

Sonic Team’s 3D kart racer for Japanese phones: weekly online Grand Prix, ghost races against rivals across Japan, and a game the West barely knew existed until footage surfaced in 2021.

Released20 Oct 2005 (Japan)

DeveloperSonic Team

ServiceSonic Cafe (i-mode)

ModesGrand Prix, Time Attack

DriverSonic (rivals appear to be Tails and Knuckles)

Available?No: Sonic Cafe closed in December 2007

Title	Sonic Kart 3DX (ソニックカート3DX, Sonikku Kāto 3DX); listed on our old site as “Sonic Racing Kart 3D X”
Platform	NTT Docomo i-mode phones, 900 and 901 series
Service	Sonic Cafe, Sega’s Japanese mobile portal
Developer	Sonic Team
Publisher	Sega
Genre	Kart racing
Players	1, racing other players’ recorded runs online
Released	20 October 2005 (Japan only)
Predecessor	Sonic Racing Kart (Sonic Cafe, 2D)
Availability	No longer available; footage of it resurfaced in December 2020

Overview

Five years before Sonic & Sega All-Stars Racing, Sonic Team had Sonic driving a kart on Japanese phones. Sonic Kart 3DX was the 3D follow-up to Sonic Racing Kart, a top-down racer on Sega’s Sonic Cafe service, and it arrived on NTT Docomo’s i-mode handsets on 20 October 2005.

Sega’s control list has no accelerator at all: you steer with the left and right keys and brake with almost everything else, so the art is in the cornering. Sega’s own page boiled the challenge down to fractions of a second and urged players to take the classic out-in-out racing line. Time Attack sets you loose on five courses, while the Grand Prix (“S1 Grand Prix” on the game’s own menu) pits you against players across Japan on a new course every week, with downloadable ghosts of rivals’ runs to race against.

Sonic Cafe closed on 1 December 2007, folded into a new portal called Puyo Puyo! Sega, and for years the West knew the game from little more than Sega’s own screenshots. In December 2020 a Japanese YouTube channel uploaded about 18 minutes of footage, and in May 2021 Western gaming sites noticed that a “lost” Sonic racer had resurfaced.

Quick Answers

The short answers, with the detail further down the page.

Plot / Story

There is no story here, just a goal. Sega’s page sets it out as becoming “No. 1 Sonic”: beat your own best times, then beat everybody else’s.

How it plays

Sega’s control list has no accelerator. Left and right (or 4 and 6) steer, and down, 1, 3, 8, 0, * or # all brake, which leaves the racing line as the real skill. Sega’s advice was to brake in good time, swing in from the outside of each bend to clip the inside, then run back out wide with your speed intact.

The 3D view sits behind the kart, a speedometer reads out your pace in kilometres per hour, and a mini-map tracks you round each lap. GamesRadar, watching the rediscovered footage in 2021, thought it looked more like an early Ridge Racer than a typical Sonic game.

Modes and courses

Two modes share five courses. Two of the course names can be read in the screenshots; the rest are held back until a source confirms them.

1. 
   Grand PrixWeekly onlineEach round ran for a week, from 10am on a Monday to 10am the following Monday, on one course. Your best time earned driver’s points by ranking, the points over four rounds decided the champion, and you could download rivals’ runs to race alongside.
2. 
   Time AttackAny timeChase your best record on each of the five courses and post it to the online rankings.
3. 
   Sonic CircuitCourseA twisting course whose preview shows Sonic’s familiar chequered hills.
4. 
   Resort IslandCourseA seaside course, shown here as the final round of a Grand Prix.

In comics, TV & other media

No comics or cartoons were tied to this one. These are the games around it. More in Sonic in other movies and media.

Characters

A small cast: Sonic drives, and the two rival karts in Sega’s screenshots appear to carry a pair of old friends. The artwork is from Sonic Scene’s own galleries; in the game they are small sprites in karts.

Character	Who they are	In this game	Stats & abilities
Sonic the HedgehogDriver	The fastest thing alive, here strapped into a red kart.	The only driver you control, and the face of the title screen.	Steer and brake only (no accelerator key)
Miles “Tails” ProwerRival driver	Sonic’s two-tailed best friend.	Appears to be one of the two rival drivers in Sega’s screenshots; no text source names the rivals.	Not playable
Knuckles the EchidnaRival driver	Guardian of the Master Emerald.	Appears to be one of the two rival drivers in Sega’s screenshots; no text source names the rivals.	Not playable

The people who made it

No individual credits are known.

How it was made

Our original page held only an infobox. This section draws on Sega’s Japanese pages, Sonic Retro and the 2021 news coverage.

Sonic Cafe and the first Sonic Racing Kart

Sonic Cafe was Sega’s Japanese mobile portal for Sonic games, and from 2001 it filled up with small titles: golf, bowling, puzzle games, an early Sonic Jump and a top-down kart racer called Sonic Racing Kart. In that game the kart sped up by itself and you just steered, choosing whether the kart or the whole course turned as you went round the bends, and you could download other players’ time-attack runs and upload your own.

Back in 3D

Sega announced Sonic Kart 3DX in its Japanese news on 20 October 2005 as a new Sonic Cafe app in which Sonic Racing Kart made its comeback in 3D. Sonic Team’s page promised sharper visuals and finer handling, and it ran on Docomo’s 900 and 901 series phones. The weekly Grand Prix turned it into an ongoing online contest, with every player in Japan chasing the same course each week.

Glitches, exploits and oddities

No bugs are documented, but the game has its oddities.

Seven ways to brake

Steering uses just two keys, but Sega’s control list gives braking to the down key and to 1, 3, 8, 0, * and #, so almost anything you press slows you down.

Racing ghosts, not people

Our old infobox listed multiplayer, but Sega’s own description mentions no live racing: the online side worked through rankings and downloaded runs of other players, raced as ghosts.

A lost game, found on YouTube

For years the West knew the game from little more than Sega’s own screenshots. The footage that brought it back to light sat on a little-known Japanese channel for months before the Sonic fanbase noticed it in 2021.

Videos & media

The December 2020 footage that rediscovered the game, and TheGamer’s news report on it.

About 18 minutes of gameplay, uploaded in December 2020 by the Japanese channel 動画投稿をする人【仮】.

TheGamer’s video report on the rediscovery.

Trivia & facts

• 

  The Grand Prix ran on a weekly clock: each round opened at 10am on a Monday and closed at 10am the next Monday.
• Sega’s page told players to master the “out-in-out” line through corners, real racing technique in a Sonic game.
• The speedometer reads in kilometres per hour; GamesRadar spotted it topping out at around 160 in the 2021 footage.
• Our old site listed it as “Sonic Racing Kart 3D X”, merging the names of the original and the sequel.

Media & artwork

The title, logos and screenshots from Sonic Kart 3DX and its 2D predecessor. Select any image to view it larger.

Legacy

Note: Sonic Kart 3DX is no longer available. It was sold through Sonic Cafe, and that service closed on 1 December 2007.

Release history

• Sonic Racing Kart Early 2000s – The 2D original on Sonic Cafe.
• Released 20 October 2005 – Sonic Kart 3DX on Sonic Cafe for i-mode 900 and 901 series phones.
• Sonic Cafe closes 1 December 2007 – Sega merges the portal into Puyo Puyo! Sega.
• Footage uploaded December 2020 – About 18 minutes of gameplay on a Japanese YouTube channel.
• Rediscovered May 2021 – GamesRadar, Nintendo Life and GameSpot report the find.

The 2021 rediscovery

Most Sonic Cafe games never left Japan, and once the service closed they were very hard to see. Sonic Kart 3DX was known in the West from little more than Sega’s own screenshots until December 2020, when the Japanese channel 動画投稿をする人【仮】 uploaded around 18 minutes of play. GamesRadar thought it looked as if it was being run on an emulator; Nintendo Life described it as recorded HDMI footage. Because the channel was so small, it took until May 2021 for fans to spot it, and GamesRadar, Nintendo Life and GameSpot all ran the story that month.

It now takes its place in Sonic’s long line of racing games, from Sonic Drift on the Game Gear to Sonic & Sega All-Stars Racing.

Further reading

More from Sonic Scene on Sonic’s racing and mobile games:

Sources

Every fact on this page was checked against the sources below. Sega’s Japanese pages and Sonic Retro were read through Wayback Machine copies; translations from Japanese are ours. Course names come from the screenshots themselves.

• Overview: Sonic Team, Sonic Kart 3DX page on Sonic Cafe (in Japanese: headline, compatible phones, modes, controls, Grand Prix rules, tips; Wayback copy, January 2006); Sega, Japanese news archive entry for 20 October 2005 (in Japanese; Wayback copy); Sonic Retro, Sonic Kart 3DX (i-mode 90x, Sonic Cafe, 2005-10-20, modes, screenshots, Sonic Cafe game list; Wayback copy); GamesRadar+, Ian Stokes, “Footage of lost Sonic game has resurfaced”, 7 May 2021; Nintendo Life, Liam Doolan, “Video footage of Sonic’s long lost kart racing game has resurfaced online”, 8 May 2021; Sonic Scene, “Sonic Racing Kart 3D X” (original infobox article, Joomla 410); Sega Retro, Sonic Cafe (launched 26 January 2001; closed 1 December 2007 and merged with the Sega Ages portal to form Puyo Puyo! Sega; Wayback copy)
• Quick Answers: Sonic Team, Sonic Kart 3DX page on Sonic Cafe (in Japanese: headline, compatible phones, modes, controls, Grand Prix rules, tips; Wayback copy, January 2006); Sega, Japanese news archive entry for 20 October 2005 (in Japanese; Wayback copy); Sonic Retro, Sonic Kart 3DX (i-mode 90x, Sonic Cafe, 2005-10-20, modes, screenshots, Sonic Cafe game list; Wayback copy); GameSpot, Darryn Bonthuys, “Footage Of Lost Sonic Game Has Been Found”, 7 May 2021 (Wayback copy); Sonic Scene, “Sonic Racing Kart 3D X” (original infobox article, Joomla 410); Sega Retro, Sonic Cafe (launched 26 January 2001; closed 1 December 2007 and merged with the Sega Ages portal to form Puyo Puyo! Sega; Wayback copy)
• Plot / Story: Sonic Team, Sonic Kart 3DX page on Sonic Cafe (in Japanese: headline, compatible phones, modes, controls, Grand Prix rules, tips; Wayback copy, January 2006); Sonic Retro, Sonic Kart 3DX (i-mode 90x, Sonic Cafe, 2005-10-20, modes, screenshots, Sonic Cafe game list; Wayback copy); GamesRadar+, Ian Stokes, “Footage of lost Sonic game has resurfaced”, 7 May 2021
• In comics, TV & other media: Sonic Retro, Sonic Racing Kart (automatic acceleration, steering only, downloadable time attacks; Wayback copy); Sonic Wiki Zone, Sonic Racing Kart (Car Rotation and Course Rotation views, citing Sonic Team’s Sonic Cafe page); Sonic Retro, Sonic Kart 3DX (i-mode 90x, Sonic Cafe, 2005-10-20, modes, screenshots, Sonic Cafe game list; Wayback copy); Sonic Scene, Sonic Drift (1994 Game Gear kart racer)
• Characters: Sonic Team, Sonic Kart 3DX page on Sonic Cafe (in Japanese: headline, compatible phones, modes, controls, Grand Prix rules, tips; Wayback copy, January 2006); Sonic Retro, Sonic Kart 3DX (i-mode 90x, Sonic Cafe, 2005-10-20, modes, screenshots, Sonic Cafe game list; Wayback copy); Sonic Wiki Zone, Sonic Kart 3DX (title screen; an unreferenced gallery caption calls the night race “a race against Knuckles and Tails”); Sega, Japanese news archive entry for 20 October 2005 (in Japanese; Wayback copy)
• How it was made: Sonic Retro, Sonic Kart 3DX (i-mode 90x, Sonic Cafe, 2005-10-20, modes, screenshots, Sonic Cafe game list; Wayback copy); Sonic Retro, Sonic Racing Kart (automatic acceleration, steering only, downloadable time attacks; Wayback copy); Sonic Wiki Zone, Sonic Racing Kart (Car Rotation and Course Rotation views, citing Sonic Team’s Sonic Cafe page); Sonic Team, Sonic Kart 3DX page on Sonic Cafe (in Japanese: headline, compatible phones, modes, controls, Grand Prix rules, tips; Wayback copy, January 2006); Sega, Japanese news archive entry for 20 October 2005 (in Japanese; Wayback copy)
• Glitches, exploits and oddities: Sonic Team, Sonic Kart 3DX page on Sonic Cafe (in Japanese: headline, compatible phones, modes, controls, Grand Prix rules, tips; Wayback copy, January 2006); Sonic Retro, Sonic Kart 3DX (i-mode 90x, Sonic Cafe, 2005-10-20, modes, screenshots, Sonic Cafe game list; Wayback copy); GamesRadar+, Ian Stokes, “Footage of lost Sonic game has resurfaced”, 7 May 2021; Sonic Scene, “Sonic Racing Kart 3D X” (original infobox article, Joomla 410)
• Videos & media: YouTube, 動画投稿をする人【仮】, video io5aP3FVV5E (checked with oEmbed); YouTube, TheGamer, video fwsjCA1wZ9Q (checked with oEmbed); GamesRadar+, Ian Stokes, “Footage of lost Sonic game has resurfaced”, 7 May 2021
• Trivia & facts: Sonic Team, Sonic Kart 3DX page on Sonic Cafe (in Japanese: headline, compatible phones, modes, controls, Grand Prix rules, tips; Wayback copy, January 2006); GamesRadar+, Ian Stokes, “Footage of lost Sonic game has resurfaced”, 7 May 2021; Sonic Retro, Sonic Kart 3DX (i-mode 90x, Sonic Cafe, 2005-10-20, modes, screenshots, Sonic Cafe game list; Wayback copy); Sonic Scene, “Sonic Racing Kart 3D X” (original infobox article, Joomla 410)
• Legacy: Sega, Japanese news archive entry for 20 October 2005 (in Japanese; Wayback copy); GamesRadar+, Ian Stokes, “Footage of lost Sonic game has resurfaced”, 7 May 2021; Nintendo Life, Liam Doolan, “Video footage of Sonic’s long lost kart racing game has resurfaced online”, 8 May 2021; GameSpot, Darryn Bonthuys, “Footage Of Lost Sonic Game Has Been Found”, 7 May 2021 (Wayback copy); Sonic Retro, Sonic Racing Kart (automatic acceleration, steering only, downloadable time attacks; Wayback copy); Sonic Wiki Zone, Sonic Racing Kart (Car Rotation and Course Rotation views, citing Sonic Team’s Sonic Cafe page); Sega Retro, Sonic Cafe (launched 26 January 2001; closed 1 December 2007 and merged with the Sega Ages portal to form Puyo Puyo! Sega; Wayback copy)