I'm starting to realize you're really similar to me. Work on one project for a long time then get bored and move on to the next leaving abandoned stuff in your wake.
No hate btw. You last longer than I do on my projects.
Anyways something I always recommend for games(and for people like me) is to make it easily moddable.
That will not only allow it to live on past completion but also many games absorb mods into them(a good example of this is X-Change Life. Minecraft also used to do this which is where we got pistons, horses and a few other things I can't think of.)