Hey, I'm really sorry you're having trouble. I would recommend deleting it then re-downloading if no error code is happening and the game just isn't responding. Sometimes things go wrong when downloading/extracting and doing it all fresh could fix it up.
Also, if you have a lot of other things going on in the background when booting the game up for the first time, maybe close them so your computer can focus more on getting the demo running.
Hopefully that works out! Just let us know if you're still having issues.