Marvel Puzzle Quest .SAR Archives

[sdryf3]

So I asked about this on another forum, but didn't get any sort of response. I've been trying to unpack the *.SAR files from Marvel Puzzle Quest, a PC and mobile game that has some really neat art of various Marvel characters. I don't think it should be terribly difficult to do, and if I had a better idea of what sort of process to follow I think I might be able to figure it out on my own. There exist several options for "Shoot Many Robots", a title from the same studio that on the surface seems to use the same format, but none have yielded any results for me yet. Here's two of the three archives (third is way too big) from the PC version (I can also provide similar archives from the other game, and how to unpack them, if necessary), hoping someone here can provide some more insight. Thanks!

[aluigi]

The format is simple but the archived files seem encrypted so: no key+algorithm = no extraction.