Hi, we're sorry you're having trouble with the game! What antivirus software are you using? And were you able to run any other Ren'Py games before? We haven't had any problems with this until now but we'll try and see what we can do.
As of now we don't have plans to release the demo on Steam. If there is more demand we might consider it but since the demo is free we wouldn't have any means to recuperate the entry fee until the full game is closer to completion.
Sorry again, and thanks for your interest!