I've been playing the demo today. It's a pretty good game so far, but I'm already getting bored of the back-and-forth objectives in the first main area. Good Metroidvanias should loop the player back to an earlier area eventually, but that's after they've explored and gained new abilities or items that enable that loop.
So far the first area has gone like this:
Talk to person
Fetch thing in next adjacent area of the map
Go back one screen and give thing to person
Gain ability
And that's okay, but doesn't feel truly earned.
I'm still interested enough that I will probably play to the end of the demo though. It does feel very polished.