First three files are for the 32 bit version of Stellar Tactics, version 0.493a
Second three files are for the 64 bit version of Stellar Tactics, version 0.493a
The last file is a patch to bring you to 0.493a only if you downloaded the older version (which isn't available now). You can ignore this file if you're downloading the installer from scratch. The currently available installer doesn't need to be patched.
The ones you want depends on whether or not you have 32 or 64 bit Windows. Most likely, you'll want files 4,5, and 6, since most recent windows will be 64 bit.
I agree that the link should say exactly which version and which OS it's intended for, but until GoG gets around to fixing it, here's what you can do:
Just click on the link and when windows ask you what you want to do with the file, it will tell you the exact file name of the file it's getting ready to download BEFORE it begins. The file name will tell you the version number (0.493a) the build number (37126) and which operating system (32bit or 64bit) the file is for. If the file name isn't what you're looking for, just hit the cancel button instead of the save button so you don't waste time or bandwidth on a file you don't need.
Also, send a message to GoG demanding that they restore the downloader links. If they still had these, it would all be automated and you wouldn't have to mess around with this stone-age web-browser download crap. Let them know that a crappy manual web-browser link-based download system is completely unacceptable, which means their promise that the Galaxy client would always be "Optional" is at best disingenuous and at worst an outright lie.
Also, be sure to vote here:
https://www.gog.com/wishlist/site/keep_the_gog_downloader_and_keep_it_up_to_date
