This looks like CoffeeScript had a baby with Rust, and I'm seriously tempted to switch from the former for my latest project. It has all features for which I am still considering adding specialist libraries to CS (promises, macros, and a bunch of ES6 stuff.) Insanely great work! The latter parts of the slides where one slide == one feature helped me have a feel for the language better than the text docs.
In it, I discuss some of the design decisions. Sadly, there wasn't any video, so I don't actually go in-depth in the slides themselves.