All fair points. I just didn't have time to add the rest of it, including more complicated and interesting endings (and story indications of what you could be aiming for). The tradeoff was to have at least something - in this case a good ending and a bad ending - so that there is a complete story loop for the player rather than a broken jam game with no ending. I had also planned a basic game of nine plants/planets (three easy, three medium, three hard) but only had enough time to add two easy and one hard. In a not-jam game I would add even more, of course.
I have a couple of random events in the game that can negatively or positively affect your resources but I had intended to add a lot more plus some probability things you would know about and could anticipate/try to plan for.
In reading about Midnight Staircase I came across Aaron A Reed's description of it for Fallen London, a game I play, and, honestly, the Midnight Staircase aspect of that game is the most boring, grindy part of it (it's also a significant part of the game) so I had that in my head as I was designing my game, unfortunately. I also, as I mentioned in another comment, lost a lot of time in the beginning because I had planned to make a game in Bitsy and then had to pivot when I realised I couldn't make this theme work in it.
I do feel that I've got the basics of a good game here but it needs time and work outside of the constraints and pressure of a jam so I've put it in the circle-back pile (although that pile is getting bigger every year). If/when I get back to it I'll definitely take everything you've said into account as it's very helpful. Thank you.