Movies, television, and games certainly don't require a wall-to-wall score. It's a mistake many scorers make (and inexperienced musicians in general), but the score can often have far more impact if it is present only when it is needed.
In fact, it is not uncommon for a significant portion of a film's music to not ever make it onto a soundtrack; most musical moments come in brief little vignettes known as cues, usually under a minute and often barely conveying an eight-note theme to support dialogue.
A couple decades ago movies realized that, hey, we're spending millions of dollars on foley to get very deep and impactful action sounds like bullets firing, explosions, etc., and that maybe some of those major action sequences have more impact if we don't score them at all. The lack of music in these cases can actually bring you closer to the action. Think about the opening battle scene in Saving Private Ryan, the invasion of Normandy.
Throughout that 20-minute battle sequence (I'm not going to link it, but I bet you've seen it) there is only one tiny section with music: when the camera briefly dips under the water in a bit of a body-count shot. That little shred actually brings attention to the fact that there isn't any sound elsewhere in the scene that isn't the visceral sound of major battle.
This is something that video games, by and large, have yet to realize. Everyone is familiar with the general level music transition to the "hunker down behind this oddly-convenient chest high wall, we have enemies a-comin'!" fast-paced music, right? Maybe that's not necessary.
Lack of music can also build tension, especially when it is released properly. Here's a great example from the first Gears of War (NSFW language):
There is no music at all until a full minute in, and when it comes in it's a barely-perceptible string pad to simply build the tension a little more. And then, 20 seconds later, release. The score continues its minimalism after that, but it's a good example of how very few lines can be used to good effect.
And for an example of something that would have had much more impact without a score, check the first thirty seconds of this:
The music here is so disparate from the visuals it almost brings it into the realm of comedy, which I don't think is what the composers intended.
Instrumentation, chord restriction, and other limitations are also ways to heighten impact. Bernard Herrmann wrote the entire famous Psycho score using only a string section: no winds, no brass, not even a timpani. I think that this small, focused sound makes the terror far more intimate, which is the same thing Hitchcock's cinematography was trying to express. Do you need an example? Of course you do:
There is plenty of evidence of the many ways in which video games can be enhanced by a better take on their scoring, elevating them to much greater heights than they have previously attained. The score truly can be another character in the story, adding interjections and subtext of its own. How can we go about effecting such change?
I think the first thing is mere education. Being able to recognize and discern good uses of game music and how they work, and picking them apart from bad, is something from which all video gamers can benefit. Ideally video game reviewers and designers themselves will begin to pick up on such nuances as well, but only if gamers writ large begin to demand it.
As we dip into the uncanny valley and emerge on the other side at nearly photo-realistic visuals, it's no longer enough just to have "good graphics". Over the next decade it will not be good graphics that win recognition, but good and cohesive art design (in truth, this is already happening). The singular artistic vision, contributed to by many -- just like a movie -- is the future of growth in games. This should -- this must -- include a much deeper understanding of visual-oriented music scoring and how it can enhance the gaming experience. We must create more immersive, more supportive scores, and the time is now for it to happen. How?
The easiest fast-track is budget. A typical film has a music budget of somewhere around 5 percent. Were we to extrapolate that to video games, we could see things like Call of Duty with $5 million budgets or higher, and that's just based on the sheer development budget (exclusive of marketing and distribution). That much money could land you the likes of Howard Shore standing in front of The London Philharmonic, if you so desired. It's no accident that the game rumored to have the highest music budget of any to-date (Final Fantasy XIII) is one of my favorite soundtracks -- and you can read a great deal about why in this blog post.
Of course, the second half goes back to education and thought investment. It's not enough for Skyrim's designers to say "Let's have a Dwaemer male choir sing the Elder Scrolls theme, 'cause that'll be awesome! And huge! Fuck yeah!" There has to be far more deliberate thought into what can be done with the music, and the myriad ways in which it can affect the setting. Thought and care must be put into the music. We've seen several examples: Jerry Goldsmith's admonition to the trumpeter on the Chinatown score, Nier's producer bowing to a superior score and re-arranging the game around it, Herrmann writing a very intimate score to support Hitchcock's very intimate movie, or the linked leitmotif discussion of Final Fantasy XIII... this is where the growth opportunity lies.
There are patches of sunlight: aside from the games discussed here, Dead Space 2, Journey, and a few other games have scores that will surprise many people... but we're still a long way off from full understanding and implementation. Publishers and developers should realize that the music is worth spending money on. Producers should think very clearly about their emotional and intellectual goals with their projects, and how to convey those to composers.
The composers themselves, who have been recalcitrant to study the more cinematic aspects of music, need to pull from the deep well of knowledge that hundreds of years of compositional experience can offer. While we've seen a move toward more well trained composers like Jason Graves (Dead Space series, among others), the large majority of game composers simply don't have the training.
People who have been in the game for 10-20 years, have a great ear for melody, and know how to work within the confines of adaptive audio, for sure, but the long narrative of music seems to have eluded us to this point. Those few occasions where the "big boys" of film have been invited in for games (like Hans Zimmer writing Cues for Modern Warfare 2) it's been to make their PR team happy with another box-art bullet point by writing a couple cues and then let others do all the heavy lifting and actual composing.
Indie games have proven that gamers are willing to actively invest brain space in game music. The BIT.TRIP series, Botanicula, Audiosurf... My Steam list is filled with games that integrate music fully into the game. Though these games are tangential to this discussion, they can serve as proof-of-concept that spending time to concentrate on the music isn't throwing money down a well.
As to the players themselves, well, they would do well to think about what they really enjoy about game music. Are they just looking for some tunes to chill to while they game, as a great many game soundtracks show? Or are they willing to take the step to become a more active audience in a game's audio-visual synergy, to invest themselves more into the experience, and reap the greater rewards?