I really enjoyed playing the prototype! I'm the sort of person who plays RPGs for the story but I found the combat interesting. I think that already says a lot about where this is going <3
I did have to restart the game since I lost in the boss battle the first time around. The big bramble kept summoning little ones and I was doomed! The solution was to kill it early the second time around, but how the boss battle will play out won't be clear until you see it in action. In my opinion it would be good to have a "Retry battle" option if you lose a battle, it would go especially well with the fact that you start each of them fully healed. I think it will add a lot to the experience even when you have your save system implemented.
Speaking of which - I do enjoy that you start every battle fully healed. I think it reduces a lot of friction compared to classic turn based RPGs where you would have to go to the menu and heal your characters manually.
Story wise, I think it works but as someone who plays games for their story I felt like I would have enjoyed if some conversations were a bit more in-depth. It's a game, so I completely understand the issue of having to balance story and gameplay content. But it's that, it's all about the balance. And people will love when you integrate story and characters with gameplay, which you already do very well - I think what made me really care about Carys and Bleddyn and where the story will go was that last boss battle.
So, to put the above into more concrete thoughts. It's good that the story portion before the first battle is brief, but afterwards I felt like the part where they bury the priestesses was a bit rushed. It's a big emotional moment, you can use these to show more about the characters to the player and make them care. Instead, I felt like the focus was on showing that Bleddyn is a very caring individual. I don't recall the exact words, but the line where Carys said "you dug graves, that's very kind of you" took me back from my immersion because I felt like she would say something or act in a way that reveals more about how she feels about the situation, rather than tal about what Bleddyn has done for her first. Is she angry, is she sad, is she trying to restrain her emotions? You've got a great opportunity here to tell us more about her.
The fact that you went for very different manners of speaking for Carys and Bleddyn surprised me, and I like that. It's difficult to give each character a different voice but you carried that task really well and the speech comes across as natural.
I really like the map art, it does give those autumn color vibes. Character portraits too, I can see that Fire Emblem inspiration in them and I love that. I think colour wise, portraits could do with more hue contrast between the different shaded sections. Think about the light - sunny days will have warm yellow light, which will translate into shadows with a blue tint, sunrise will have orange light with purple shadows, artificial light can be anything. Colouring with that in mind can give art a specific vibe and I think it makes it pop more overall. If you want an example, the illustration I sent you the other day is more of an orange-ish light one with purple shadows. I used layer effects (multiply, overlay, etc) to shade it but layer effects can help a lot when picking colours for pixel art, too!
I don't know what you're doing to resize the screen and keep the pixel art looking good, but I like it. It still looks really crisp!
Overall I think this project has a lot of potential and I'm looking forward to playing more when you release the full game, or when you make another prototype! I want to see what Carys and Bleddyn get up to next!