Bought a game and went to download it and was met with a 403. Sent in a ticket but I have yet to hear back from support.

Is this something that is affecting everyone or am I just lucky?

This isn't the first game I've bought from GOG but it is the first time I've run into this problem.

I just noticed a few threads with people seemingly experiencing the same problem. Best to report it to GOG support as they might not yet be aware and it seems like the site may be experiencing technical issues which is unfortunate. ;o/

Different browser should solve it.

Did you install the GoG downloader? If not then clicking on the download link with the GoG downloader option set to on will give an error. Set the downloader option to off or install the downloader to get your game.

I've done it a few times myself when I forget about turning the downloader on or off :D

Support should reply to you in a few hours. You posted this message at about midnight Poland time, so support was (probably) sleeping. They should get back to you soon-ish though. You did get the automated reply though, right? 403s are usually encountered when the CDN sees a different IP than GOG does. The link you get to download your game through the browser has a session ID that is dependent on the IP and valid for a few minutes. If you are behind a proxy server, it is possible that the CDN sees a different IP, thus returning the 403.

Using the downloader should bypass such problems.

On the weekend? Well, maybe.

Depends on the category of the ticket. Support does work on Weekends, but in fewer numbers, and they prioritize the tickets they respond to.