Nice graphics and gameplay. I liked how the camera scrolled, the combat and just the overall look of the game. Though, I found a few bugs. One bug was that I got clipped out of the map.
Here's a screenshot:
https://gyazo.com/32b3a17a8107be7e865d4ec2a9b7c86b
Another thing that you may want to improve is the movement. When I played it felt a bit off and buggy, the character is something clipping when moving for some reason. I think it might feel a bit better if you increase the speed? I don't really know.
The music felt kind of repetitive, but I guess that is placeholder to get the demo out?
I'd say this is a great idea, I like the way you have to explore for yourself. It kind of reminds me of the first Zelda game. But the great downsides are the movement, the bugs and the music.