As far as your prototype goes, a lot of the criterias don't apply, and I'm sure you know what's missing. So let's stay positive!
I really dig you artstyle. I'm sure it has a great potential. They're kinda subtle, but I did notice the chains were slowly swinging, that's a nice touch!
Your music is also very cool, I didn't mind listening to it while writing this feedback. Nice job!
Other things I noticed:
You said on your game's page that you could attack using Enter or Return, but it doesn't do anything on my end.
I'm guessing your game has three rooms, since when I went to the far right on the third one, I fell below the screen. If it wasn't supposed to happen, I'm sorry if it's my fault.
Nonetheless, it's a cool demo! I'll be waiting for more!