I loved this, especially the boss fight, which was a real highlight for me from an encounter design perspective.
The art is stunning, and it's so polished! I didn't spot a single issue or bug. For a first game, I think it's an outstanding achievement and you should be so proud of what you've achieved.
While I could try and pick out areas for improvement, I just don't see it as necessary. It held my attention and I finished the final fight with ~10% of my health left.