Books and games aren’t really comparable.
Games are a pretty unique media.
And like I said, the line is a thin one.
Let’s use the upcoming Planetfall as an example.
In the paradox forums, someone suggested assymetrical victory conditions.
Lennart Sas said it was a good idea, and something to consider for an expansion.
That’s because the game as is has been designed and now it’s being made.
Adding something so central as a new victory condition (well 6 really because if 6 starting races) would be challenging to put in now.
So far so good, expansion material. Everyone’s happy.
Now, what if Triumph revealed that they had 8 different victory conditons already done, and 8 different races, but that you were only going to get 6 and 6 because they’d decided to withold already created stuff in order to get more money of you.
People would be pissed.
It’d be better for them to focus on the 6 original races, make them dammed fun, release the game, get feedback from the community at large, issue a few patches, and then go make race number 7 and 8.
That to me seems the more honourable course, and more profitable too I imagine, as it responds to the community.