Pretty solid demo! I haven't gotten to the boss at the end yet, but I'll give my feedback on what I've played. The combat has a solid start! One MAJOR thing I gotta say is that not having combo finishers and just cycling the same two attacks 1-2-1-2-1-2-1-2 is very unsatisfying. So having combos end, and also maybe varying up the animation on each swing (like how Sora in kingdom hearts has 4 different animations for each swing in his 4 hit combo, since you yourself said KH was an inspiration) could go a LONG way.
Also, each monster feels like it has WAY too much health and takes too long to defeat. Like no regular enemy has that much health on the harder difficulties of Devil May Cry, and if they do, its a late game enemy that you are stronger and have more ablitites to dispatch that foe with. And having multiple groups of enemies with that much health is a pain.
But I wish you the best and for you to improve the game as much as ya can