And with that, all caught up on the new GOG releases for now (barring maybe Jazzpunk)! STALKER comes of course, very highly recommended. Not much else like it (Metro 2033 did not quite cut it), but at least you get a very large amount of hours of gaming from the three games, even if they don't all play quite the same, they're all incredibly atmospheric and have the ability to deliver many memorable experiences. Clear Sky is the least prized of the bunch, but it still brings enough recommendations to get included.
The Banner Saga is another solid pick. Definitely won't disappoint in the graphics/audio department, but the gameplay can be slightly hit-or-miss as it's a bit different than the traditional expectations of a strategy RPG, and impressions indicate there's a fair bit of confusion over the upgrade system, as it's possible to spend resources on characters that die or leave the story without much notice, and there's a bit of flak over the final battle. Still, there's promise under the flaws, and with luck the subsequent chapters will improve the formula and continue to deliver the very impressive audio/visuals of the first entry.
Octodad from what I gathered, is worth a more than the quick glance I first gave it. It didn't really interest me until I started reading the impressions. Now I'm convinced it's definitely a game worth looking in to, if you want a humorous, original experience. Controls are sometimes a little frustrating, but the game is short enough that it doesn't really hinder the experience much, and in some ways, the tricky controls are very much intentional and add to the humor.
The last addition is Risk of Rain, another roguelike-like or something, but this time with co-op, which really drives the experience from good to incredible from impressions. Has plenty of unlockables as you'd expect. Lots of dying, lots of enemies to fight, and very hectic. Also many different classes to try out, so there's quite a bit of replay value in it as well.