How does X work?
First, read all the Tips and Tricks, which you can access from the button in the top-right corner of your screen.
Where has the waterway recipe gone?
Waterways are now accessed with a shortcut button or keybind, just like blueprints.
What mods would you recommend?
For quality-of-life, see X-QoL.
For add-on content mods, see Freight Forwarding Pack.
For more difficult enemies, try Armoured Biters (make sure to enable custom nests in mod settings), Explosive Biters, Frost Biters, and Toxic Biters.
For more interesting environments, try Alien Biomes.
For more complexity, try AAI Industry, Krastorio2, or Very BZ (website). In particular, I'd recommend Natural Gas, Tungsten, and Noble Metals.
In order of complexity:
- AAI Industry
- Natural Gas + Tungsten + Noble Metals
- Very BZ