I agree that the line is blurry, but I think there's a workable line.
1. You are still given a monopoly over selling your game, and someone else can't just make the same game using your assets, so at least you get to make money from your work via copyright.
2. It's a game, so I would argue that it's not worth as much to society to let you monopolize selling of a game mechanic as opposed to, say, a mechanical design. (I'm fully aware of patent controversies, but we're talking about games so I'm staying at broad strokes.)
3. I think there's an argument to be made that games are more like art than machines, and thus they count enough as speech that over-protecting IP rights in games would have a chilling effect.
1. You are still given a monopoly over selling your game, and someone else can't just make the same game using your assets, so at least you get to make money from your work via copyright.
2. It's a game, so I would argue that it's not worth as much to society to let you monopolize selling of a game mechanic as opposed to, say, a mechanical design. (I'm fully aware of patent controversies, but we're talking about games so I'm staying at broad strokes.)
3. I think there's an argument to be made that games are more like art than machines, and thus they count enough as speech that over-protecting IP rights in games would have a chilling effect.
Just some thoughts.