I actually considered commenting on the contrast of the music and setting, but personally it seems like an artistic choice to have it contrast heavily with what's actually happening.
But the corpse eating stuff we both think is pretty disturbing and a bit unfitting, it more reminds you at zombies.
That's textbook culture shock. If you actually play as an elf they go into more detail as to both why and when it is done.
#Minor Spoilers#
Some of the text you see playing an elf suggests that it is how elves transfer their knowledge and culture. When an elf eats the flesh of others, they gain the knowledge and skills the other possessed. It is also suggested that they usually only eat the flesh of those who have asked them to do so, though you, the player, are given the choice to not follow this.
The idea of something like this being unfitting exists because in our culture the act of cannibalism is unthinkable and the idea of it being presented as something normal or even beautifully weirds us out.
Imagine in your mind an island with two tribes on it. Each tribe governs itself but whenever they come into conflict over something instead of going to war they host a game in which two teams try to capture one of the other teams members, bring them back to their tribe, and devour their heart. The tribe of the winning team gets to decide the outcome of the overarching conflict.
Now, at first glance this seems horrible, and maybe it is depending on your perspective, but the most casualties of any war they have ever experienced has been exactly one and that's because this isn't a hypothetical.
