Probably, as much as I hate saying it, but its likely.
I pretty much ran out of time. So much more important things require my attention and time now and I can't afford to work on this project without having a negative effect on my life or education.
However, 6D will likely make a comeback in a different form. Source could own this concept much better than what could be done on the HL1 engine, with the advent of physics and the ability to life objects. Also, I could always propose the game idea to a company and have it work that way, or perhaps use a better engine that could make it its own thing.
Like Turnstile, I will not delete a single file just in case some of the resources may be required later on.
A few awesome Ideas spawns from this however. Such as Zero-G Deathmatch using Sprit's Zero-G field capability. That would require very little to accomplish, perhaps 3 months of steady work, and some decent models.
Another Deathmatch Style is one where you can run on the walls and ceilings openly like some weird riddlebox arena using gravity shifting and each major surface has its own gravity. That would also be a great mod, but would require some tedious coding.
Of course, there is no such thing as failure, because in failure I still succeeded to Learn a lot and will need the knowledge in the future. I learned a tremendous amount about texturing for some reason, and My skill with entity work has increased considerably.
Unlike Turnstile, this mod is very unlikely to be adopted unless moved to source.
Also, A team would have helped. I misjudged several inhibitions there.