That (maybe) would have worked in the olden days of physical disks or catridges. Today it is trivial to keep the game on steam with zero sales (or almost zero).

If lawmakers wanted to pass a law that actually made this happen they needed to stipulate a cut off date (and potential compensation) as well as rigid rules about what one can do with the released code.

> and potential compensation

Why would there be a need for compensation. Copyright is only granted in the first place so that more things will (eventually) enter the commons. Rolling back the perversion that is the current copyright terms doesn't need anything to balance it out since the current sitation is already so unbalanced in the other direction.

Very few and they still make 90+% of sales before then. A price worth paying

That dynamic has changed a lot with multiplayer games which are in continuous development. For instance DayZ just hit record player numbers after nearly a decade:

https://www.reddit.com/r/dayz/comments/11nlu70/recently_dayz...

But even if that's an outlier, online games can have a surprisingly long tail where the game remains profitable even if the player count doesn't grow anymore (as long as the developer supports the game at least).

Practically only games that are continuously updated have longer shelf lifes. In that case only the original version would have to be opened after 10 years and later modifications would have to wait ten years after their release.