I love the Photosynthesis comparisons, Wholly. That never even occurred to me, but, yes, you’re spot on for calling out the various similarities and differences. I mean, they’re both ultimately about a sun.
I hope your friend gets to try more instability effects. Especially if you guys start to include yellows or (gasp!) reds. I also think the random event deck is appropriate once you’ve played a game or two, and it adds more of a “we’re all in this together” dimension to the instability.
-Tom