Hey I recently bought the standard version of the game because I didn't know if I'm gonna like it but now that I've played a couple of hours I really enjoy the game and would like to have the specials of the Collector's Edition. Is there any way to upgrade your nomal edition in the future like how it's possible on Steam and with other games here on GOG?

yes you can just search for the update on the store

Oh you're right, thanks a lot! I couldn't find it anywhere on the product page so I just assumed there is no such thing.