• Theme: I think you did a pretty good job representing 'Take a Breathe", where the balloon takes up air in order for the Player to go higher. Adding a consequence of the balloon losing velocity when out of air is a nice touch.
• Gameplay: Narrative is cute, and gameplay is a nice challenge, being careful not to lose your whole breathe too fast.
• Implementation:  Enjoyable and aesthetically pleasing, there was a time when fighting the boss that throws shapes at you got laggy for me.
• Presentation: Music and sound effects fit the game, the music is beautiful.
• I believe it was unique, cute and fun in my experience, I have not played a game where you play as a balloon before and it loses air.

Amazing! Very fun indeed, great attention to narrative, with a personal touch and subtext. I agree with the other comment: the death animation is really good! Way to go! I think that after the death, you could replace "You lost" (in the narrative text) with "You blew it!".

That's more of a "relationship word", and also a pun. I'm a casual gamer, so I couldn't get past the 2nd level, so the story didn't develop fast enough for me. I expect there's the possibility of reinflating, eventually?

I loved the bold choice of metaphorical images to compose the narrative. I imagine the thought process was something like: take a deep breath -> we are like  balloons in love -> we feel inflated or deflated by some romantic happening. Love requires energy, another word for energy could be gas, and so on.