It's a really fun concept, and that roar is truly terrifying when the dragon wakes up! That scream when the player dies is kind of hilarious, too.
I think it's pretty cool that the player becomes heavier as they pick up more stuff. The implementation of a 'sound' meter was pretty impressive, I'm not sure how I would approach programming a mechanic like that!
I did notice that the mouselook sensitivity is extremely high, so that might be something to work on improving in your next game (or if you continue developing this one).