After discovering that the DirectX SDK was half a gigabyte large, I kind of took a step back. If I was gonna get the same results as icetigris, which was likely, was PIX really worth such a massive download? I decided that I wasn't that desperate, at least not yet.
So I went and looked a bit harder into unpacking Bastion's PKG files. I found a guy who said he managed to do it, and after asking him about it (luckily he has an active blog), he gave me a link to the source code. Unfortunately there were no builds, and it was programmed in C# (which I have no knowledge of), but I downloaded Visual C# Express and managed to compile it.
It was a command-line program, as I expected, and after fiddling with it I managed to get it to extract files from a PKG file (specifically the one containing the files of the mechanical Pyth). What it produced was an XML file, which was just pointing to stuff, and a new problem: an XNB file.
I figured that this XNB file contained the graphics. Some Googling seemed to confirm it: XNA games, which Bastion is one of, commonly use XNB files to store most resources.
So while looking around to see if I could somehow open or unpack these XNB files, I found myself back by the guy who gave me the code for the PKG files. Apparently he'd also made a program to decompress these XNB files. So, I did the same as before, downloaded the source and compiled the command-line program. I had it figured out fairly quick and managed to decompress the XNB file. Now this is where it got hard.
What it gave was not a PNG or GIF file, not even a JPG. It gave me a larger XNB. I asked the guy who made the program about this, and he said that that's as far as he went, since all he wanted to do was port the game for Mac and Linux (or something like that), which required only the decompression of the XNB files. But I needed to convert them into images.
And so began my adventure through Google. I cannot tell you how many hours it took; how many websites I opened; how many paragraphs of technical jabber that I read. All I can tell is that I thought more than once of giving up. But I just couldn't. Through all of this, I downloaded numerous programs, a plugin for Paint.NET (which I had to download as well since I don't use it), I even tried learning C# & XNA myself. None of it gave fruit.
But finally, less than an hour ago, I found it. A simple little program someone managed to conjure for modding Magicka. It claimed that, among some other things, it could open XNB textures and save them as images. I had already downloaded programs that said they could do this, but those had failed. This one, however, was different. I had already downloaded an earlier version of it, which allowed me to open XNB files and view the images, but I couldn't do anything with them. This new version however, could save them. It had multiple options, BMP, JPG, TIF, but I went straight for PNG, hoping my head off that it would work. And it did.
There was something that seemed like a snag: the image was on a black background when I viewed it. Horrific memories of icetigris' sheets flashed in my mind: was I doomed to the same fate? But upon opening the PNG in GIMP, I saw the sweet, beautiful truth: the background was transparent. Nice, clean, alpha-equals-zero transparent. I zoomed in, looking at the sprite's edges: anti-aliasing was there. Half-opaque pixels, making the sprites look as beautiful as ever.
And so, I had done it. I had solved the puzzle.
I had ripped pure sprites from Bastion.