I think you really nailed the theme here. I like the simplicity of the mechanics and the emotional message you're going for. I sincerely love this game and would love to see you develop this further.
If you had more development time, I think the pacing needs some attention. There were moments where you nailed it and others where it didn't quite hit. Specifically when the pressure builds then relieves. I like that balance. But I wonder if there's space to fit something in between. I feel like the variation is not as detailed as it can be.
The only major bummer for me is making it to the end of the game only to have to restart from the very beginning after I died. Definitely consider a checkpoint system! It was an emotional journey that had this excellent, powerful payoff at the end abruptly cut short. If not checkpoints, perhaps some kind of health pickup. I was so immersed in that last battle and while dying wasn't the worst thing, having to start from the beginning felt unnecessary.
This is a strong submission and I wish you all the best!