This hits me really hard. I always try to keep a relationship with all my friends, and I feel awful when someone says that they will never talk to me.
#### Narrative I think red heart represents instincts and will to not let her go, while the blue heart represents reason and empathy and the will to not suffer anymore because of her. I played 3 runs, and I kind of understand that at the end of the game you can balance red and blue answers to define what type of relationship you will end up with: lovers, friends, or strangers.
Besides what you wanted to say with this game, you conveyed emotions, reinforced by music and feedback. Keep adding/improving visual and sound feedback to boost the experience!
#### Gameplay I think the gameplay need to be faster or more complex, because as a player I want to know the rest of the story or at least be engaged by puzzles or high paced action (think of Undertale), but depends on the type of player you are referring to.
I loved the heartbeat feedback, and more than anything else I loved the breath mechanic. This made me feel like i was in the game, and i feel bad because it remind me of such personal episodes (but it's ok).
I hope with all my heart you will keep develop games like these, no, even better. I always feel these games will help people who play it to better analyze the relationship with theirselves and loved ones.
Sorry if I committed grammar errors. Keep it up!