As the C64 was dying, Jon Wells was out there trying to save it. This was one of Jon’s big efforts to try and save the scene, and bring one final Last Ninja to the C64.
Jon created a series of demos, and music was created to try and convince System 3 that they could make one final game in the series.
Jon was planning to allow the Ninja to interact more with the background of the game, and be able to walk on the grass. Therefore not being restricted to just moving on the path. This was shown in a test demo of one of the Last Ninja 2 levels, where the Ninja could actually go on the grass.
A map was even created of one of the levels proposed by Jon to be in the game, but sadly System 3 turned down Jon’s proposal to bring the game to the C64 (Even with Jon willing to take the whole project on himself), so Jon moved on.
All that exists are a series of previews, the scanned map and lots of cool music by Feekzoid (The intro tune incomplete) and Jon for the game.
Joerg Droege informed GTW64 in 2017 that X-Style were about to take the game on with permission from Jon Wells in 2003. The team was interviewed in an earlier issue of Scene World magazine: http://sceneworld.org/emu/swo08.html
In particular CJ/X-Style was doing the game by himself, doing a brand new engine. Bas Bertens was working on the graphics, and Soren Lund on music. No permission was gained from System 3, suggesting that they would release the game unofficially and possibly with a different main character. Nothing ever happened, so it sounds like it never got past the official planning stages.
Case closed… this is all that exists of Last Ninja 4 on the C64…
Contributions: Kai Spitzley, Joerg Droege