The art and soundtrack are amazing! You managed to create a great Castlevania-like atmosphere.
I thought the enemies were well designed. As for the difficulty, I definitely found it to be on the hard side, haha. That's not necessarily a bad thing, and I also have skill issues, so there's that. It felt like the mobs were designed around the player's weaknesses. The ground mobs shoot projectiles while you have a short-ranged melee attack. Sometimes 4 or 5 mobs would pile up in a small space and shoot projectiles in series so it's hard to close in on them. You have to jump towards the flying mobs and get close to them, but they deal contact damage, so you need to be quite precise with your moves to get in close enough to attack, but not close enough to get hit in turn. This makes the the game feel difficult to me personally, but I liked the difficulty. The double jump felt very useful too!
Unfortunately, I wasn't able to save my fox friend in the background, but I had fun trying. Cheers!