The documentation suggests to me that you will simply want to create a new Package for the 1980 version in this situation.
If the developer of the 1979 version is still active and might be considering their own 1980 version then you might want to create a new competing project (I’m guessing not).
Other choices that occur to me are:
- The 1979 version is completely superseded by the 1980 version - you could continue the version line of the existing module Package. Just make it a major version increment.
- In some situations, providing both editions of the game from the same module might be the best choice. Here the players decide at “run-time” which version they want to use.
My feeling is that creating a new project should be a last resort, to be taken where two editions of a game or the owners are irreconcilable within the same Project.