Just installed RE, and noticed that Galaxy had been installed, too (I never had Galaxy on my PC before, and I don't want to use it). And when I launched the game, it went through Galaxy first.
How comes? Why is this not mentioned in the game description?

It's not really a big deal: I uninstalled Galaxy (and blocked access to Galaxy via my firewall), and the game started nonetheless. But why perform a hidden installation of Galaxy in the first place, and why don't launch the game directly?
It's against all computer ethics (and against some other rules as well) to install software without the users permission, without even telling him in advance?
A promotion exercise for Galaxy? No, I'm joking - I think it's obvious that such an attempt to promote Galaxy would backfire.

I guess you missed this?
I certainly hope it does.

The link says that GOG offers 2 versions, one with, and one without Galaxy, and that the customers can decide. This would be ok, if it were true - but it isn't, at least not for RE.
When I look at my RE entry, it contains the headline "GOG Galaxy Installers", two downlaods, one labelled "RE:IS", and the other one is "RE - 32-bit Installer". There is also a little note underneath the 2 installers saying "The above installer includes GOG Galaxy client ...".
I admit that I missed the references to Galaxy, but this doesn't change the fact that there is NO installer not containing Galaxy.

Update: I found it! Under "More", there is an entry "Classic Installers"! Well hidden, I must say.

First of all, thanks to you for sending me link. I don't read all announcements and posts, so it may happen that I miss one or the other. My personal opinion is that GOG should have sent a message to all customers because it's a very significant business change in this case.
That customers are offered the "Galaxy" versions without an indication that there are also "Classic" versions available under "More" speaks for itself: GOG is going for "unintentional Galaxy installations", a questionable marketing practise in my mind.
As far as I'm concerned, now that I know this is going on, I can avoid the Galaxy installations easily (as long as the "Classic" ones remain available).
Don't get me wrong: I don't mind Galaxy as an additional platform for customers who don't like to manage their games themselves, and don't mind DRM and GOG spying on what they are doing (with other words, people who are happy with Steam, too), but this experience tells me that GOG is positioning Galaxy as their main platform, and, I guess, eventually as the only platform, as it's quite costly to maintain two platforms simultaneously.
I notice that GOG is moving closer to Steam, step-by-step, and I find less and less reasons to prefer GOG over Steam. For people like me, Galaxy and the way it's rolled out is a great promotion exercise for Steam, and it makes me sad (but who cares?).