That's a quick work on the first person mode, and I really appreciate how much detail you put towards immersion in the game. Can't wait to play it!
Also I would prefer if the protag has a soft breathing voice for when she's nervous/running/masturbating rather than no voice at all. As for when she's orgasming, I'm imagining a voice where she makes tiny moans in really short periods, like a series of impulses instead of continuous moans, and she would moan as if she's trying keep her mouth shut.