The game will be great no matter what the monster looks like (considering it's a shape shifter and all) and I still love the premise and atmosphere. I will absolutely play the new demo and full game once it launches so no worries there.
I made a discussion about the monster design where I go into more details on the Steam Discussion forums for the game. I invited others to talk about their feelings of the old vs new design and linked to this demo, but so far no other comments yet. I did see about 2-3 comments on Alpha Beta Gamer's new demo video that were talking about liking the old monster design better and they had about 6 upvotes each. I'm eager to see what others have to say about it as well.
Good luck with the game no matter what you decide, it's your game after all :) I'll play it no matter which monster it has and suggested some ideas to use *both* in the Steam Discussion thread. Thanks for taking the time to get back to me!
I encourage others to provide their thoughts on the old vs new monster here as well as on the Steam Discussion thread here:
https://steamcommunity.com/app/2948790/discussions/0/4845401230250331093/