Everything that happens in the game has a reason. Even every sentence that is spoken has been placed with a purpose. I'm just showing the pieces of the puzzle one by one, and at some point, there will be enough pieces to understand the story.
The game's goal is to create an exciting and fun journey. That's why the tone of the story might change at times so that I can continue developing the narrative alongside it. This fun itself is a part of the story, and I can't tone it down...
Finn was angry that day because Riley had gone without him, and Riley expected him to come and apologize. That's why this time, he was already frustrated and let Artyom insult her. But later in the game, we see that he still loves his sister, and they make up. Though Finn might change along with my mood, I'll try to keep his character the same.