Update to fix problems in the demo version

Thank you to all the victims of the “Limb-Severing Devil Case” who are enjoying the full voice demo version!
I have updated the demo version to address some minor issues.

• When adjusting the SE and voice volume in “CONFIG”, a test SE or voice will now play for volume confirmation.
  
• Fixed an issue where clicking during option fade-in would only play the click sound.
  
• Fixed other minor bugs and typos.