I think there's some misconception here. SotE 's funding ran out but the game is still under development by the community. We open sourced it under the GPL license ( https://github.com/Calandiel/SongsOfGPL )
It takes 1-3 minutes to generate a planet with your high performance computer precisely because the planet generation system isn't bad (in the sense of accuracy). SotE runs a tectonic simulation, calculates fluxes of magma heat, runs multiple climate simulations at different timescales, runs erosion simulations, figures out watersheds and lake placements by running a physical simulation of water movement and drainage, generates soils using a physically based bedrock erosion model while also coupling it to the water movement simulation, generates glaciers along with their movements, runs a plant growth simulation and so on.
And that's just a short summary, each of these steps is much more detailed than just doing the simplest thing possible (to give an example, if you pay close attention to oceanic plates youll see that as they get older they get denser, leading to deeper oceans on average at one edge of the plate)
Calculating all of that is a *ton* of work and that's why world gen takes a long time. 1-3 minutes sounds about right. On my laptop it used to take 5-7 minutes to run full world generation.
As for the game, assuming you're talking about the version from itchio, there isn't any. At that point in development it was only a world generator.
Source for all of the above: I coded around half of SotE if measured by lines of code.