Hey! I just finished the demo and have some feedback!
First of all I already love the characters and cant wait to play the full game!!
Things that I noticed are:
When you use an Item in the inventory it would be great if you would stay in the inventory so you can use an item again on another character f.e antidote now it always leaves the inventory and you have to go back to it for each character.
I had a little grapic bug at the beginning but that was just while walking into a tree. 
I had a little bug in the Mine when you drice the cart. When I had a second fight while in the cart I was outside of the cart while still on the rail after the fight. It still made the sound as if I was in the cart but the graphic was gone.
At the End of the Demo while fighting against the Lady in White her name was seen during the Fight but afterwards it said "????" again.
Again thank you so much for letting me play the game it´s really an honor for me!!