As the other half of this project's developmental team, I feel it necessary to respond to Norbez.
Quite bluntly, there is no message about gender identity, except maybe one suggesting Social Justice Warriors lay off a bit. Picking your sex is just part of pulling yourself together. It's a tutorial to show how some aspects are mutually exclusive. Stop reading into it so much.
The game is 20-30 minutes long. The 'creepy' or 'loudly speaking' things you mention all come down to the big reveal at the end. It ties everything together.