write music for Ben's video game

My little brother’s designing a video game and I’m writing the music:) WHAT FUN! It’s an RPG where the story is basically central to the game, so alot of it is similar to writing for film, and then there’s the zillions of little fighting and map bits. I have an idea of taking a page out of Wagner’s book and using a recognizable little motive, or a whole “theme” for each element in the story, and then use the appropriate combination of thematic material, set in whichever mood is right, for each scene. There are 6 characters in your party, plus 4 or 5 other main characters, so they each have a theme, plus there’s a theme for each of the 8 magical elements in the story, as well as a title theme. So let’s say the character Melinda has a heated conversation with the bad guy Eric down in the ice caves. The material would be derived from Melinda and Eric’s themes, as well as the ice theme, and set in a highly energetic, sort of “angry” mood. Erm, so far all I’ve written is Melinda’s theme, LOL. But it’s really pretty:D