I bought Two Worlds over ½ year ago and requested multiplayer CD-key and got it as reply from GOG support but now I can't find it anywhere. It wasn't an email but somewhere on main GOG.com website.

that has been removed. If you don't have saved it, request a new one I would say.

Yeah, I don't have it saved anywhere. I hope they'll resend me one.

I think so, I assume they will have somewhere a database with the assigned keys. Just give them a bit of time, today is friday afternoon, could be that they are already off for the weekend. But I keep my fingers crossed for you, that you will get a response still today :)

Thanks, just received it! Now well wait until my little brother gets his, he just bought copy for himself and requested a key.

BTW. May I ask why was the support message feature was removed from GOG.com webpage?

They accidentally broke it when they updated the site after the PR stunt. Then they removed it, in order to fix it, but that was 3 months ago, and nothing has been heard of it since.

You could infer either that A) they are not very good programmers, or B) customer support is not a priority for them.