Darlink's Project is not completed yet and many new expansions will be released in the future for this game. The base game is complete and have all the features and stuff that I designed at the beginning of the project and on the top of this base game will be made some expansions. This does not include that updates have stopped and the game is done. This game will continue to receive fixes and updates until all it's working at its best.
The first fix for this game will be made as soon as bugs are found (I'm working on the expansion so I will retest it later). Needless to say that all content in this base version (Darlink: The Beginning) are free as any update and bug fix for it.
Next expansion (as already said on the site) will contain new and original contents and, as such, will have a little fee applied to it. You're free to create additional stories for this game as it is released under GPL (see the license file included in the game for more info), but the same won't apply to the expansions.
Lastly the expansion fee will be decided later based on content. I will let you know when I have more contents and, of course, a clearer view of it.