Keywords include: Drama, Slightly theatrical, Orchestral feeling, Stylish, Cinematic
As the narration in the video is the most important thing, the music shouldn't steal the main role but remain in the background.
The sound effects are very important (maybe even more than the actual music) and they should support and preferably enhance the story.
You can ignore the currently used sound effects and replace them with better ones.
Avoid synthetic feeling in the music. Remember that the visual appearance of the video dates back to days before synthesizers..
Get inspired by the visual feeling of the video.
In the final mixing make sure that the music doesn't distract the viewer from hearing the narration.
Note that the music can but doesn't have to be playing throughout the video (see inspirational links).
Do no modify the narration track as it is (except what for what is needed when mixing it to other sounds).
The two deliverables are:
1) single readily mixed sound track (music+effects+speech)
2) music and effects as separate files.
See links for video and voice over.
NOTE THAT THE VIDEO ON MICROTASK SITE IS AN OLD VERSION (see the last reference video / files for actual version).