Codex Gamicus


First Conception[]

Development of Sonic X-Treme (codenamed Sonic Mars) started soon after the SEGA Technical Institute finished developing Sonic and Knuckles. It was to be released on the 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 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 that 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, 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 video 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 series video 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[]


  • Chris Senn
  • Chris Coffin


  • Mike Wallis - Producer
  • Hirokazu Yasuhara - Lead Designer


  • Ofer Alon


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


  • Howard Drossin