There is no voice yet (I haven't got around to getting the lines) and yes the demo ends after the CPU or player hits 0
Last update was 2 days ago as of my reply, plan to update the game as frequently as possible! You can check the patreon page where i'll be announcing updates and such.
Demo has just been updated with bug fixes!
Hello, this has been fixed in the newest version. I'll be pushing a new demo version soon.