You guys have got a pretty cool game going here! I played all the way to the end of the demo and then started over to try a few different choices. Here are my thoughts.
The first thing I have to mention is the voice acting. I normally don't like voice acting, but the quality of this took me by surprise! It didn't sound amateur, and more than that, it was enjoyable. The voices suited their characters and definitely added to the game. The music blended in well, and the sound effects were high quality and used well.
Graphics & UI
The paper texture of the dialogue box and choice of colors gives the UI a mid 1990s vintage RPG feel, which I like. One major issue was that I could find no way to exit the game from the title screen. I had to go into options to quit the game.
I thought the backgrounds were good for being photo manipulations; it looked like some care had gone into them. However, the throne room feels out of place. The rest of the castle is white and palatial, but the throne room looks like a grim dwarven hall, or the lair of a super villain. I don't have any strong feelings on the sprites one way or another, which isn't a bad thing. The character design is a little bland and predictable, but it's drawn well. Rory's sprite is the exception... I just love it. He looks scary and impressive, and like he is a person that is going to make things HAPPEN. The dude has screen presence!
They all fit into familiar archetypes and roles that I've seen a hundred times before, so they easily could have come across as boring or insufferable, but that wasn't the case. I expected some agonizing from Calista about how she wasn't good enough to be a queen. The fact that she doesn't whine about it excessively, or think of herself as unworthy of the man she loved, saved it from being annoying and it kept her a likable character. The trope where the prince defies convention and marries a peasant is stale by now, but you went out of your way to show some of the actual work and sacrifice that entails, as well as hint that there were deeper motivations, which makes all the difference. Kiran's role and costume telegraphs "bad ass," yet he is refreshingly free of edginess or angst. I didn't think that Maddox had much presence or personality. I'd pegged her as "spunky partner in crime," but her laconic voice is at odds with the narrative description of her as energetic.
Altogether, I kind of just got the feeling right away that I liked these people. My favorite character was Balder because he had the gentle, protective, intelligent and responsible thing going on.
I'd describe the characters as "safe". Familiar, enough deviations to keep from being boring, but there's also not enough that's unique about them to make them really compelling. Of course, this is just the beginning of the story so that could change quickly, and I do like that they aren't exaggerated. There's a fine line to walk between boring and caricature.
Story and Writing
The writing needs editing for grammar. I saw many punctuation errors, some words that were capitalized that shouldn't have been, and twice the word "passed" was used instead of "past."
The pacing is good. It hits all the right beats. It jumps right into action and spends just the right amount of time on every scene, no more or less. Every page of text felt relevant. That's huge! Wandering dialogue and narrative is the most common problem I see in visual novels, but this game knew when to address something, how long to spend on it, and when to move on. For example, it would have been easy to let the argument between Calista and Balder drag out forever, but their argument was long enough to believably resolve the weighty matter, yet concise enough to stay interesting and keep things moving.
The major problem with the story (and the game) is that it appears to set up a mystery right away that doesn't feel like a mystery. As a reader familiar with this kind of story, I felt assured enough that all of the commotion at the castle was because our protagonist is a very important person, probably a princess with magical powers, her prince is using her and will probably betray her, and she's going to be traveling with good guys that look like bad guys. The game's setup asks plenty of questions, but there's nothing to suggest that I may be surprised, and if I already know the story, then why keep playing? The characters were charming enough and the pace quick enough that I did, but I think you could make the beginning more compelling by introducing something more surprising and unexpected.
I also think you need a better hook. I almost passed over this game because of the synopsis; only the art work pulled me back. It uses passive voice, gives away too much, and could be more concise. You could also do away with the overused phrase, "web of deceit." The writing in the game is much stronger than the synopsis, so I feel like you're doing a disservice by not having an equally strong synopsis.
Edit: I revisited this today and wanted to add, is fierce traditionalism really a "plague"? The narrative is taking a strong moral stance on a contentious issue that is the source of much debate: conservatism versus the ideals of progress. Both positions have their up and downsides. It might be more interesting to leave authorial opinion out of the story for the purpose of opening up ambiguity. When creating fantasy worlds, I always caution writers to beware of assuming modern moral stances on ethical and political issues, which is particularly important because your new world may not have experienced the same events that led to our own current beliefs, which changes the viewpoints of what your inhabitants would consider good and evil. I think leaving ambiguity for that may be more interesting than assuming that the customs of tying status to heritage is backwards and barbaric.