Oh, that's not a bug xD It's the true ending of the demo.
"End of the demo" = You made it through o.ob
"Game Over" = You died and could have done things differently o.ob
Ah. Alright thank you for letting me know that I wasn't actually hit with a bug for once, If there is a bug in something I'm almost always unlucky enough to come up against it! I guess the ending seemed a little abrupt, and potentially deadly, to me and since I'd just read about a problem that others had with that encounter (while trying to find out if I was just flat out doing something wrong) I assumed the usual had happened again. Good to know the issue this time was only me being a twit!