selling game assets

I've unlocked most of the regions in FUEL now. It's a massive gameworld. And, since the developers used satellite imagery to guide its design, it feels pretty real.

I enjoy the races and offroad roaming the game offers, but the expansive setting keeps me wishing I had a gun too.

What if game developers sometimes sold their game assets to be used in other games? For example, what if Codemasters sold its great world from FUEL to be used in a shooter-RPG?

At first, I was thinking it would be cool if other types of gameplay could be incorporated into the same game, but there's only so much any platform can process before you have to start sacrificing things like field-of-view. The next best thing is to use the same setting for different, separate gameplay.

Selling game assets (objects, scripts, etc), rather than just graphics engines, would help offset costs for the producing developer. It could also shave off production time for the buyers and perhaps help them focus on their strengths.

There are some downsides, of course. Having a unique visual style, for example, definitely helps in marketing. But can't the sale of game assets at least be a feasible option?