I love how you use the engine and the combat system mostly, but I was turned off by a large amount of bugs, some of them game-breaking, starting with first minutes of the game. There are passability errors, wrong effects for artifacts, the fade out effect that never fades in, and the first cutscene has a good chance to permafreeze you in place if you move in the wrong direction. These are just a couple I've remembered.
I think you really need to playtest it better, even if it's just a demo,
Good luck with the game, hope to see it finished someday!