Great job on the atmosphere; the lighting really adds to the ambience! I enjoyed exploring the dungeon as I managed to find the sword quite quickly. It might be beneficial to increase the range of the sword swing, as with the current range I often ended up having to stand still and let enemies approach me to ensure I wouldn't get hit.
Having the stamina regenerate more slowly when you're low is an interesting mechanic; it certainly adds tension to the combat having to manage it more carefully. However, it is very punishing outside of combat, as it results in a lot of downtime waiting for it to regenerate. It could benefit from a resting mechanic, which could normalise stamina refill but would leave you vulnerable so it could not be abused in combat.
Overall, its a pretty neat dungeon crawler!