Sure, not a problem and a fair thing to ask! It only communicates locally with the Steam Client to check for ownership. The check still succeeds if Steam is in offline mode and the game is owned for example. If Steam is closed or the game is not owned there, it will silently not use any further Steam functions. It does this through standard Steamworks API functions that are made for checking ownership and initializing the API.

Edit: To be clear, the Galaxy API implementation is roughly the same as well, I realized I didn't specify this.

The question I was answering was about the ownership check, and whether it uses the internet or local methods to do this. The game itself does not communicate with the internet in any way and only interfaces with the Steam and Galaxy clients (if available, i.e. the client is open and the game is owned on that service) using their respective official APIs. Yes, it will track achievements via Steam like any Steam game would, and on Galaxy at the same time, if you own the game on both of these services. This also means achievements can be simultaneously unlocked on both services if you're a double-dipper, which is the biggest thing people used to ask for. Both of these services automatically track play time when their APIs are initialized and I cannot turn that off without turning off the APIs entirely. Regardless, all of this functionality remains completely optional and is easily disabled by removing the applicable DLL file for the service you wish to remove.