We (that is, artists in general) typically come into games with a soloist mind set. This is cultivated from our time as amatuers, where most of us seem to have been producing art by our lonesome, where we have immediate control and visibility over all elements of our work at once.
This entirely reasonable trend among amatuers a might change as game development is increasingly more accessible, thanks to readily available software like construct, unity, and unreal. Only time will tell.
But, once we enter into game development we typically join a team of artists, wherein we specialize in producing art for a specific family of assets; characters, environments, etc. At this point we tend to fight the same old battles we've always fought at this point, throwing our entire bag of tricks at any particular task set in front of us. When an entire team does this without considering their art's place among everyone else's assets, the final look of the game comes together looking like a mess. It is akin to every musician in an orchestra trying to play the entire score.
Of course, this can happen even if it's the project of a single artist, since you will be working on a variety of disparate assets which will only later be seen together. However, the team based nature of most game development only further lends itself to this problem of tunnel vision.
Its crucial to remember that each asset must work in concert with all the others, just as certain hues and values are regulated to certain areas of a single illustration to produce harmony.
For art leadership, it is especially important to be aware of this type of tunnel vision both in your own work and in the work of your teammates. Although it is valuable for everyone on the team to recognize this concept, it is ultimately the leadership's responsibility to coordinate everything.
The principle can be sumed up thusly:
The entire screen of a video game is the illustration, not any particular asset.