From now on, I will be versioning the official to-do list of the project.
It's located here:

From this you can learn about my plans in more detail,
however the technical entries are a mess - they aren't exactly designed to be understood by anybody else because these are mostly just quick notes for my own use.
If somebody joins for real, I will make every single word of it understandable.

If you're interested, you can still read the GDD section which is mostly ideas and concepts!
Remember though it is still a subject to change and many features are not yet completely described and/or properly planned.
That's because first of all, I'm focusing on coding a fun game!

To open the list, you need to download this awesome open-source program.
A quick glance: