Is game music still lagging behind film music, in general?
The work of composer John Williams in film always acts in a support role yet is always memorable. In Jurassic Park, Jaws, Close Encounters of the Third Kind, Star Wars, Indiana Jones, and countless other films, Williams' music manages to captivate movie goers without distracting them from the visuals and dialogue. We remember his music, but we remember the story too.
There are definitely inherent differences between films and games in the ability to predict audience experiences (timing, order, focus, etc). But some differences are not inherent.
Williams' scores are among the most memorable in film history largely because of the method he uses: leitmotifs. He ties musical themes to central characters, to recurring scenarios (such as Indiana Jones action scenes) and recurring images. How often do game composers attach recurring themes to story elements?
I've mentioned before that lessons are more deeply ingrained and more easily recalled when they are attached to strong emotions. Likewise, characters, events, and environments can be made more memorable by giving them their own musical themes.
Music can also associate things. If a cave and a mine share a musical theme, then the player will perceive them as variations of one environment. If a brother and sister appear separately in a game but share one musical theme, then family traits become emphasized over individual characteristics.
Conversely, music can call attention to differences. Attach a dark musical theme to a villain, activated by a sphere around the character, and attention will be dramatically focused on that villain wherever he or she walks. The player might be in a bright and cheerful town when the music takes a dark turn, pointing out the villain's presence in a powerful way. Another example is to give two similar-looking pubs vastly different music. Despite looking basically alike, the player will perceive them in wholly different ways if one has a slow, sad violin and the other a ragtime piano.
Leitmotifs are not always the best choice for game composers, but they should be in every composer's toolbox.