I would like to buy the game on Steam but unfortunately due to it's missing age rating I 'm even not able to have access to the Steam shop website of it. Is there a way to solve it?
Ah, I'd guess you're from Germany or China? Steam has OBSCURA blocked in both of those countries because it claims the game has "frequent sexual content". We disagree, but Steam gave the game a high age rating and has refused to lower it.
Unfortunately, there's nothing we can do about this right now. You can buy the game here on itch.io (sorry about the lack of regional pricing, we'd turn it on if it was an option) and you will get a Steam key with your purchase that should work like normal, but that's the only option we can offer right now.
You should get a Steam key if you get the game through Itch.io, yes. You'll have to connect your Steam and Itch.io accounts (it's in the setting menu), and then on the download page there will be a button for getting a key.
And to clarify: Steam is the one that decided our age rating. We wanted a lower rating.