Thank you for making this game! I really enjoyed it. Apart from the pretty art that everyone already pointed out, I also think this game has a very unique mechanism and great writing.
SPOILERS BELOW
Having two paths of storytelling determined by the combination of the first two choices still leading to the shared endings was a cool idea. For my first two playthroughs, I changed these two initial choices and still went down the poisoning path both times, so I totally didn't expect to discover a different side of the story in another playthrough. It was a really pleasant surprise that the characters can spend their day out and show us more about how the previous master died, which added to Cyrus' character depth. It's interesting how the choice to swap the ring replacement still got included in different narratives - dirty ring after gardening vs taking ring off during cloth fitting. It's also cool that some choices can directly lead to missing out a large portion of storytelling (if you don't give Mikael the antidote, the entire day will pass with him bedridden + if you refuse to go out with him, the day will just be skipped until he comes back.) While it's straightforward to get all 4 endings, it was very interesting to find out about these mechanisms and try to see all possible dialogues. The dialogue also shows minor changes depending on earlier events, like Mikael saying he doesn't care about other stuff, only how Cyrus felt, would have the variation that says no matter what his sister says about Cyrus included if the letter from his sister was received during the day. This kind of minor details really shows the attention that you put into making the game.
The writing was great. I really like both characters and didn't find any typos either. To be honest, I expected a lot more toxicity knowing that the theme was toxic love. In my opinion, toxic love was only present in the bad end. Other than that, I think Mikael liked to flirt with Cyrus but wouldn't really cross the line. In one of the neutral endings, Mikael showed that his way of loving meant prioritising Cyrus' happiness, even if it meant letting Cyrus go would hurt himself deeply. This, along with the dining table dialogue "Do you really believe that I am despicable enough to force you?" convince me that Mikael might at most be an ignorant aristocrat, but he's really not a toxic love interest (apart from the bad ending which his personality differed of course.)
At first, I wanted to help Cyrus kill Mikael because Cyrus seemed to really want to kill him. But from the first meeting, I started to find Mikael adorable and it made me very hesitant to do anything mean to him. My stance quickly went from "Let's poison the porridge because vampires might be more sensitive to the scent of blood" to "I'm definitely giving him the antidote. Do I really have to torture him with the catalyst later to get the bad ending??" I got the good ending for my first playthrough which was really sweet, and this made it even harder to go back and be mean to Mikael. But as a completionist, I had to do it anyways. During my attempts to see all the dialogues, I often found myself trying to kill him, but always felt too soft-hearted and backed out whenever such an option was available. Particularly, the scene when Cyrus reprimanded Henri, causing the fire, it was very difficult to ignore when Mikael was so vulnerable and asked for help. This scene felt the hardest to come back and collect the dialogue because Mikael was really pitiful and sad when Cyrus ignored him.
And finally, I want to mention that the art and music are very nice too. CG arts, character sprites and the little bats are all really cute. The lone blue wounded bat for the bad ending was adorable and pitiful, while the two loving bats in the good ending and the game page are super cute! Thanks a lot for your effort in making such an enjoyable game.