This seems like a well scoped, high impact game. By putting the player in the shoes of people forced to make sometimes easy, but usually tough choices, it highlights how some people are just forced to lose something to chance, and how those choices and opportunities aren't afforded to everyone. By being a text based game with (seemingly) binary choices, and 9 choices for each of the 3 characters, it keeps the scope somewhat reasonable, despite being a solo project. Also, the GDD is very dense and well formatted, the best I've seen so far. It's good that there's no lose condition - you can strive for better, but you can never do so poorly that you die, which I think is good for keeping the tone from getting too heavy (plus, most people wouldn't actually be killed by a heatwave unless they made terrible choices or got incredibly unlucky)
It's a little disappointing that there's no indication for the visual or writing quality, or direction aside from the key scene, which demonstrates more of an impactful moment rather than general vibe (which is what it's supposed to do, I know), but it's otherwise a good document which demonstrates a good plan for a game.