I saw the video playthrough of it, and decided to download the demo to see how much it had changed. There was a lot of cool things (love the shotgun) and extra cutscenes added in, but some of the scenes that happened seemed odd...
Also, there are a LOT of typos. I don't mean to sound nitpicky, but this many typos for a game with lots of dialogue disrupts the story for me. I know some previous posters have pointed it out, however, I'll still point some out since you did ask for feedback. Some might be personal preference, though, but consider changing:
The vast majority of "your"s were the incorrect placement - it should be "you're" or "you are". "Your" is the possessive pronoun (eg. your mod, etc.)
"Slepping bag" should be "sleeping bag"
Lots of capitals in the middle of sentences. Particularly, most of the misplaced capitals were the second word in most sentences.
"I love you to Mom" should be "I love you too, Mom".
"Itho"? Perhaps I just saw his name wrong in Cave Story all this time? I thought it was Itoh.
Anyways. (I can't get spoilers to work properly up there...)
Your demo seems to focus more heavily on dialogue than gameplay, which I don't actually mind, except for that one cutscene that seemed to be taken entirely from Cave Story itself. Fortunately, you made Quote in your game move automatically, but having that placed in was just awkward. I'll assume this scene is meant to be cut out of the finished product.
The dialogue was sometimes amusing (Sue breaking the fourth wall with that fanfare, haha), but a lot of it seemed unfitting for the characters, in my opinion. King saying "Quiet, Toroko!" for example, didn't feel like something he would say. Maybe it's just my interpretation, but I always had this theory that King wants to do anything to protect Toroko and while he is stern at times, he is never flatout rude to her. I thought Itoh would show more signs of being panicky, but he seemed pretty chill throughout the demo.
The Doctor cooking breakfast and being a cook? I laughed a little at that.
Nice effort so far, and hope to see more progress on it soon. I am playing the right demo...0.200, is that right? If you've fixed all these things, oh I'm so sorry for wasting your time. But all the other links seem to be removed.