Cool game! The premise is neat, and the game looks really good. There are some bits on lighter backgrounds where I feel like enemies are too low contrast & don't stick out enough, but the darker forest areas were phenomenal.
If there's any sort of visual indicator you've just taken damage, it's too subtle to be noticeable. I know you start flashing red if you only have one heart, but it'd be nice to have a damage flash or something once you take damage in the moment. It'd also be nice to have some sort of visual feedback after picking up a heart.
There's someone sitting by a fire you talk to right after the tutorial level. The sound effect has a higher frequency talking to him than when you talk to those grey smoky things. I'm not sure if that's intentional (I guess to accentuate how lifeless the smoky things are?) but to me, it feels like the higher frequency is too harsh. Maybe scale them both down?
Combat was really smooth, but I feel like the player moves too quickly. I feel like the sword attack range was a bit short. The attack animations were incredibly clean, though! As was the rolling animation. Generally, the animation in the game is great, but those two really stuck out.
I really liked the sound effects & music!
There was one section (sort of north of the tutorial area) where it was red dirt(?) by green grass. I'm not quite sure what the red patches were supposed to be. From first glance, I thought it was going to be lava.
A couple of mistakes in dialogue:
In the opening, it says "every people" at one point. You probably want to switch this to "every person" or "all people." Also, another section talks about "towers, acting as a shield..." It'd be better to switch that to "towers to act as a shield."
On the southeastern side of the first forest, there's a grey smoky thing that says "the other side of the forest is full of monster." It should be "the other side of the forest is full of monsters."
Overall, this was great! You can really see the care that went into it, and I am excited to see more of the game!