This was a really neat project! I like the premise and the framing device of it being a letter. You could release it as-is and it'd be a fairly polished product, but some more art would really take it to the next level. I liked the moment in the story where there was a storm and a thunderclap sound effect played - some more moments like that would add a lot of excitement. Also, the idea of an "Archeocook" is so fun!
Feel free to disregard this next advice, because it's about the writing and obviously that's up to you with what direction you want to take it, but I almost felt that the story should have been more ominous. It sort of starts out that way, but the ending has happy music and a happy conclusion. I think a more ominous atmosphere would fit in better with the story being about some future Earth, presumablty ravaged by climate change and environmental crises.