I very much enjoyed the visuals of this game, although I'll echo what others have said about the color palette being too bright. While I liked the visuals, I found that the story itself became difficult for me to get through because it hit a few of my pet peeves in writing. I'll be constructive here because I think you have an interesting story and I would like to see it become stronger in the next installment! I'll give my feedback without spoiling too much.
1) There were several moments where the dialogue matched the narration. It didn't make sense to have a character tell us a fact and have the MC repeat it through internal narration. For example, when Colin is first introduced, the MC and Colin engage in a conversation about their friendship since childhood, the MC's role as Colin's father's ward, and Colin's father. Right after that dialogue, the MC repeats the same information through internal monologue. The first few times were fine, but it began to get overwhelming as the pattern continued. I feel as though it should be one of the two things: a) we find out info through dialogue, or b) we find out the info through internal monologue. Having both is redundant - I feel as though you should pick one during various scenes in the game. Mixing them up occasionally works too.
2) This brings me to exposition. I think it could have been handled better, in the "show, don't tell" fashion? When the second MC was introduced (in the Vanilla area of the kingdom; I apologize, I forget her name) , she points out to Colin everything mentioned previously (childhood friendship, relation to his father, etc.) Colin would know all of this already, so it becomes odd to point this out. If you think about how the conversation would play in reality, I think it would help in tightening the exposition. The same goes for when Cassandra declared her title and father's title to her own governess, who would already know that. I understand the audience does not know that, but I believe it can be displayed through events and actions.
3) The amount of sympathy held toward a character without much backstory or reference. The second MC dotes on how she is (and I'll paraphrase): ugly, dim-witted, and could never be liked by Colin (in the romantic sense). But...it makes it hard for me to sympathize for her when there has been nothing to confirm those claims. No one in the city has made a remark about the MC's appearance nor has the MC looked into a mirror to contemplate her looks. The MC also seems somewhat intelligent through her monologues, and Colin seems to like her. So the MC's claims seem to be contradicting what the audience is reading. Now, it can be argued that the reasons behind her low-self esteem will be revealed later in the game, but for the MC to make such claims early on in the story doesn't make me feel sad for her. Again, this falls along the "show, don't tell" rule. I don't think the difference-in-class argument is a strong enough excuse, because the MC and Colin talk to one another without any indication that their class divides them.
Again, I'm giving this feedback because I really believe this story can make a splash. Since this is the pilot/episode 1, I can see the future episodes being better and better with each step.