On the note of webassembly's text format (WAT), it's a fantastic introduction into a low level assembly. Wasm is a virtual stack machine, and it's strongly statically typed, so WAT is surprisingly readable. That being said, if the WAT you're reading wasn't hand-written, it's probably going to be unreadable anyway.

Here's an example of some mutex operations in WAT: https://gist.github.com/devsnek/9274f1420b7641d1b6c34141921f...