Oh how I adore Proteus. It's equal parts minimalistic, enchanting, and really, really difficult to describe to people who haven't played it. I mean, the point is to just walk around an island that looks like heaven as imagined by the tiny, tribal colony of Atari 2600s that have been forever exiled to your closet. And then things kind of just... happen. Except when they don't. (See what I mean about the description thing?) Ultimately, though, it's about taking in wondrous sights and sounds. And, as part of a brand new beta update, you can now share yours with everyone else. And not just with screenshots.
So here is, in my opinion, the coolest bit - though it only unlocks after you've played through once:
"The 'postcard rack' appears below the title screen. If you take a screenshot using the ingame function (on F9), this is saved to a Postcards folder in your user data area ('Documents' on PC). World and location data is encoded in a strip of pixels, so that the game can regenerate that view (and the world) from the screenshot. You can use this as as a save and restore mechanism, a souvenir collection, or a way to share discoveries and favorite places."
So basically, other people can look at your postcards, say, "Gee, I'd sure like to visit that place and maybe follow an amorphous yet mesmerizingly bouncy forest creature through it," and then do just that. Which, given Proteus' focus on discovery and good-old fashioned gawking, is really, really cool.
Beyond that, this update adds new creatures (one of which is apparently "quite rare") and new music. A full playthrough also throws the chance of "wild" islands into the mix, which can do anything from "spawning lots of extra creatures of one type to [creating] some dramatic visual differences."
Also of note: an actual release window. Proteus is now set to hit Steam "sometime around the end of October." For now, though, I highly recommend giving the beta a go. Find a quiet room, put on some headphones, and just marvel at the otherworldly serenity of it all. Yeah, Proteus is pretty hard to describe, but once you're actually there, it'll all make perfect sense.