I managed to run the game. My Linux distro installs Java 21 by default, whereas your jar requires Java 24 which caught me off guard. I don't think there is a technical reason for the game to require such recent version of Java.
Basic instructions would be nice to have. Took me a while to figure out that you can change the substance using the mouse wheel. I walked around with the character but it didn't seem like it interacted with the terrain at all.
Using raw LWJGL and compute shaders is an interesting technology choice. I haven't played with the terrain rules but I am curious how are they parsed. Is everything after { } in rule = { injected into the compute shader? Looks like it.
Overall, what you have is more of a prototype. I think falling sand games have a lot of potential overall for a 64x64 jam.
All things considered, having no web build will limit your audience for the game. If you want to stick with Java, you could use something like LibGDX which has a way of exporting the game to Web.