Hi, just bought the game, no DLCs yet.
When I run the game it asks me if I want to enable online features.
When I try to register my account the game asks me for a key, provided by GOG.
From other forum posts it seems like there should be a menu "Serial keys" under the "More" button in my library - however I dont have that. I tried looking for the key everywhere, even in the game installation folder, but with no luck.

How do I get the key? Or registering online is not that important?

Edit:

Ok, found the key. For anyone having the same problem:

1. you have to go to the gog.com website, can't do that from the application (how stupid is that?)
2. got to you Account -> Games
3. click on the game
4. in the popup click on "More"
5. Serial Keys menu is there

that is quite a convoluted way for doing a simple thing like that to be honest :)

The online components of ToME and how they interact with the GOG version are a little special, but I'll clear them up the best I can for anyone wondering about what to do with keys and such.

One really should register their keys on ToME's main site. Online isn't as important for a GOG copy as with one from the same site, but some functions are done online still, like an online item vault. You have live chat and such too, and your unlocks save on your profile as a sort of cloud save. As long as you use the same account, you can drift away from the GOG version to Steam or the main site's version, and you keep your progress with unlocks, achievements (there are tons of both), what DLC you can use, etc..

Donation calls will always be there though, I see them most when I reach Level 10. Thing is, ToME itself runs by donations and the GOG version is a donator's edition. On the main site donation is how you pay for DLC, but for a GOG version you can still donate to support the game. Donations still buy you more item vault spaces, which also carry over to wahtever version.

All this said, there's a game option that shuts off all online interactivity. There's a lot of warnings with that which you'll want to read in the option's description however.