Yeah I have to agree. Green hearts are odd. That isn't the toxic-looking forest green I associate with poison; it just makes me wonder if the character is a plant. Which would be cool.
You ruined the mid-game plot-twist!
Also, that music Aklyon is quite cool, but might get annoying if you are constantly on health-alert in the game. I'd prefer maybe more tranquil, sad music when you are low on health, sorta like you might die, so the music starts to die too.
It will make the player more attached to there character. There is this character, which is of their own design, wandering through this harsh abyss with music which symbolises their death.
I mean can you imagine what emotions would seep into your brain when you hear
this in a tower you are climbing? It would make you think "I have to do this! No time to lose!". It would bring the player closer to the character like never before.
Or even
this as you wander through the grassy land with 10% health, trying to avoid being hit by the harsh environment ahead. These will immerse you into the environment even more than normal.
I half-kid here, but the music should not be upbeat if you are low on health as it can get annoying if you are constantly at that health, feeling always on the edge with the music fast-paced like the Pokemon Black/White song. I would feel more fragile and cautious when the music is more tranquil and i'm low on health.
An example is when a slower-paced song comes onto AI War, especially
this, I usually think of the task I have ahead of me: 5 planets captured, 60 to go through, overwhelming odds. For that brief moment in time, you feel like you might not be able to live up to the task you have been set.
If put at the right moment, music can make you feel a range of emotions. A bleeping every now and again does not. I think Galaxy 2 or a game I played recently did that often and I hated it so much.