[2023] Focus on Single player experience.

Eco is targeted towards and developed for a multiplayer experience - but also highly configurable, there is basically very few things you couldn't configure to your personal liking, as other people in this thread already mentioned. If you have any specific questions about that, I'm happy to help.

We don't have any XML files to modify things, I guess you talk about .cs files, which are just program code. It's modding when you do that, all relevant settings are available in config files. Anything specific you miss?

Those settings will purposefully not be made available in the client, due to them only being suitable and supported to be changed for dedicated servers and having high complexity. They are all part of an config file, though and can be changed via the Server UI.