Warning: WYS spoilers ahead :)
There is a game called "Will you snail?" (WYS) by Jonas Tyroller. If you go to the Squid's presentation room after fixing him, there is some binary, which turned out to be a puzzle, and is being solved on WYS Discord (#WYS binary decrypting (read pinned)). For more information look at the doc.
wys arg decrypting toolkit is probably the part that you came here for - the other stuff are small scripts and bruteforcers.
There is a lot of tools. The main part is wys arg decrypting toolkit :), but there are two algorithm bruteforcers, some key bruteforcers and multiple scripts.
Scripts include key tester (doc) and index table with L2 key finder (doc).
There are two algortihm bruteforces, niether of them has good documentation :/. Each one has it's own folder and readme.
algo_bruteforce's readme - algo_bruteforce tries random expressions and checks if it makes a valid message.
ab_v2's readme - ab_v2 tries random instructions and checks if it makes a valid message.
There are multiple (now three, but two of them are unfinished and one of those is not even in the repo) key bruteforcers. The first one (doc) is simple one-threaded C key bruteforcer.
TODO: other key bruteforcers - doc