I just played your game on "Hard" difficulty and I loved it! The game is really well made and I fell in love with the "Darkest Dungeon" like map design.
Just a few things I would like to bring to your attention:
1.) The first boss in the sewers killed me two times because I did not fully understand the battle system back then. The small fights were over after 2 or 3 turns so this fight was the first that took way more turns. Maybe I should have read your explanation about the battle system more carefully but if I remeber correctly it was not mentioned that you could use "Arts" and "Exeed" multiple time in one turn as long as no attacking move is used. When you have 100 EP you can use 3 Support Arts and finish your turn with a Chain or Attack Art. Of course a player will eventually find out about that but was it your intention that players had to discover that themselves?
2.) When you reach the part in the sewers where you can walk around with your character there are a lot of boxes. I noticed that all boxes which are either empty or unable to be opened are shown as green while the once that can be opened are shown as red. I walked straight past the red one because I thought to myself: "Why bother with red boxes when you cannot even interact with green ones?!" xD In most games green as a colour is used if something works, red if it doesn't. Maybe I am the only one who got confused xD
3.) After I discovered the whole dungeon map I had to backtrack to the first area in which you can freely walk round. I did not notice that you can interact with the computer console to unlock the next room. It doesn't look any different to other things that are in the room. And since this is the first console a player is very unlikely to click on it. Later on when you are looking for the spare part to repair the bridge console a small sparkle tells you where to look. Is it possible to change the design/colour of the important consoles so that they are easier to distinguish from plain consoles?
4.) I really like the fact that you can see the whole dialog by pressing "A". It is also a very nice feature to be able to save mid dialog by pressing "Q". I have never played a game like this where this is possible. Sadly I did not know this until I had to go through the sewer boss dialog a third time and just pressed the button to see if I could skip it. Maybe you could explain these dialog features as well :) I don't want players complain that they have to go through all the arena fights again because they lost the final round.
5.) Last but not least xD Shame on me but I lost a character in the final arena fight. I wanted to load my save before the fight to retry. Thats why I just clicked on "Chain" to faint my second character for the loading screen to pop up. But what is this witchcraft?! She comes back to live!!! Awesome. The game only explains thats characters that are knocked unconscious will be back after the fight. If I remeber correctly it doesn't tell the player that after a couple of turns the character will come back during the fight as well ;)
I hope I didn't criticize to much. My only intention is to thank you for sharing that wonderful game with us and maybe I am even able to help you improving it :)
Thanks again. And I hope the full game will be released tomorrow *____*