First Conception

Development of Sonic X-Treme (or Sonic Mars) started soon after SEGA Technical Institute finished developing Sonic and Knuckles. It was to be released on the SEGA Genesis in the style of the last 4 games in the series.

However, people soon lost interest in the dying Genesis and turned their focus to its add-on, the 32x. It was then given the name Sonic Mars, after the codename for the 32x. The game would be an isometric 2.5D scroller with an eventual 3D view. The development team made the game far too complex for the 32x's limitations, so the project was moved to the Saturn.

SEGA Saturn

Once the project had been moved to the SEGA Saturn, it was being developed in two halves. One half (led by Chris Senn and Ofer Alon) made the core game. While the other half, led by Chris Coffin, made the boss engine.

In March 1996, SEGA representatives went to check in on the project. Their responses were average, but they pointed out the excellent boss engine and requested the game to be scrapped and re-done with that engine only. They were given a Christmas 1996 deadline after that.

The team then had to work extremely hard to meet this deadline, working up to 16 hours a day on the project. Due to this many members of the team fell sick and the project was delayed. After that, once the project had passed its deadline, the game was cancelled. The programmers continued to work on the engine though, although the pitch to the SEGA executives including this engine was rejected. Alon left SEGA soon after.

Leaked content

Little other content was officially revealed, however a test engine pitched to SEGA was sold for a whopping $2500. The disc was later purchased again and the disk image was leaked online for public download.

In 2006, Senn opened a website to further leak information about the game, some never seen before. He leaked gameplay footage, concepts of a playable character called Tiara and even some level designs. He announced plans to recreate the game, but that effort was scrapped in early 2010.


This game has been blamed for the failure of the Saturn in the West, as they failed to release a landmark game for the system. Instead they released 3 games including: compilation disc entitled Sonic Jam, which featured 7 sonic games ported from the Genesis.

Second was Sonic R, a racing gaming infamous for its music and poor gameplay. Finally was a Saturn port of Sonic 3D Blast. Sonic would not see his true 3D debut until the Dreamcast with the Sonic Adventure games. People have speculated that this game was the inspiration for Sonic Lost World, as there are several similarities in the gameplay and other aspects.

Notable People



  • Mike Wallis - Producer
  • Hirokazu Yasuhara - Lead Designer


Ofer Alon


  • Ross Harris
  • Fei Chang
  • Richard Wheeler
  • Stieg Hedlund
  • Alan Ackerman


Howard Drossin

Sonic series
Main series:
Sonic the Hedgehog · Sonic the Hedgehog 2 · Sonic CD · Sonic the Hedgehog 3 · Sonic & Knuckles · Sonic Crackers · Sonic 3D · Sonic Adventure · Sonic DX Directors Cut · Sonic Adventure 2 · Sonic Heroes · Shadow the Hedgehog · Sonic the Hedgehog (2006) · Sonic Unleashed · Sonic the Hedgehog 4 · Sonic Colors · Sonic Generations · Sonic Lost World
Handheld series
Sonic the Hedgehog · Sonic the Hedgehog 2 · Sonic Chaos · Sonic Triple Trouble · Sonic Blast · Sonic Labyrinth · Sonic Pocket Adventure · Sonic Advance · Sonic Advance 2 · Sonic Battle · Sonic Advance 3 · Sonic Rush · Sonic the Hedgehog Genesis · Sonic Rivals · Sonic Rush Adventure · Sonic Rivals 2 · Sonic Chronicles: The Dark Brotherhood · Sonic Colors · Sonic Generations · Sonic Lost World
Sonic Classics · Sonic Jam · Sonic & Knuckles Collection · Sonic Mega Collection · Sonic Gems Collection
Sonic Spinball · Sonic Drift series (Sonic Drift) · Mean Bean Machine · Tails Adventure · Tails' Skypatrol · Knuckles' Chaotix · Sonic the Fighters · Sonic R · Sonic Shuffle · Sonic Pinball Party · Sonic Riders · Sonic and the Secret Rings · Sonic Riders: Zero Gravity · Mario & Sonic at the Olympic Games · Mario & Sonic at the Olympic Winter Games · Sonic and the Black Knight · Sonic Jump · Sonic Dash · Sonic Jump Fever · Sonic Boom