Wowza, love love love the 2D art~! Incredibly polished, soft, and super detailed. From an immersion perspective, y'all nailed it! Blended super well with the tunes and the sfx!
I think the only thing I could critique is mainly just gameplay, one of my favorite things with Vampire Survivors is when you narrowingly dodge hordes of enemies through small gaps. I felt like you couldn't really do that in this game due to the hitbox. Not sure if maybe having a large floating sword asset is a great idea, even though it's so pretty, because it prevents me from understanding where visibly I'll be taking damage. Maybe having something below the sword might help to show where that box--or sphere--is to help the player do those rewarding moments in bullet heavens. Could be a flame from the furnace you're defending. Y'all got a fire theme going, maybe the flame becomes weaker as you take damage.
The game also became "semi-repetitive." I did like that you added the defense of the furnace element, but I almost wished there were more powerups versus the three I saw: 1) the movement speed increase, 2) the axe, 3) and the kunai. Wasn't sure if the game had more, like an increase to attack speed or power for the sword, but I feel like those small adjustments might've helped to engage me more.
Regardless, I feel like if the critique is asking "for more," that's probably a good thing cause it means y'all made a fun game. Good stuff and solid submission~!