In short, the release is delayed (and has no set date) because it's presently more or less a solo project that I'm able to work on during evenings and weekends - still progressing forward, but slowly. The good news is that eventually it will come out, there's no rights or legal issues stopping me from releasing the game! I would definitely recommend, though, to just keep the game on your wishlist and put it out of your mind for the time being - it'll be a while :)
In the future I might reach a point where I can go from this very small scale to a slightly larger development, and in that case I'll also have the means/resources to share a lot more concrete things, dev updates, and so on. For now though, it'll stay an in-development passion project for the forseeable future!
I do really appreciate the support and interest, and will make sure any significant news are shared when possible :)