I agree with the previous comment. The difficulty of the game never really got any higher, but if it did get appreciably harder, I wouldn't be able to read the story. It's definitely a hard balance to find. The emotional state definitely didn't feel impactful. If it changed my fire pattern, like sad made them fire in a crying-like downward arc, angry was a charged burst/blast, then I would have to pay attention to it and it would tie the narrative and gameplay together a lot more cleanly.