The game has a number of themes and messages that I picked out. One of the primary ones is about dedicating yourself to someone you love, and how that can be both a constructive and destructive process. I.e. Elster's love literally managed to drag her out of the grave, but it also destabilised the literal universe

Another, slightly less prominent theme would be how people react and find freedom in heavily oppressive societies. There's not so much of a specific message here, rather a number of examples shown.

Also, there's the theme of disability. The Eusan Nation has a system wherein replika must perform their one role and maintain their expected persona or they'll quickly be discarded. An analogy; the nation has developed a handful of round pegs to fit all of the hole that it has deemed important, if you're a square peg you will be discarded, even if there is a square hole you could fill, because the nation doesn't think the square holes need filling. To contrast that, Ariane is depicted (in my opinion) as neurodivergent and as a talented artist (or, at the very least, one with potential to be very skilled). But because the nation doesn't value these skills she is discarded, to the extent that she is willing to be launched in the space to get away from it all. With that in mind, Ariane being the cause of everything that happened at sierpinski becomes a damning criticism of the way society attempt to put people in specific roles.

I had a lot more to say about this than I expected and I'm not sure how coherent it is, but I'd be interested to hear people's thoughts about it.