If you want to dive right into what seems like the first key "interesting" idea, it's here:

https://tutorial.ponylang.io/types/actors

If you know a few programming languages I think you should be able to guess what the syntax does from context.

And then the next key idea is here:

https://tutorial.ponylang.io/reference-capabilities/referenc...

(Although I think the first actual interesting I idea I saw was "Destructive read" under https://tutorial.ponylang.io/types/classes#functions , but that's clearly just an isolated quirk, not part of the core idea of the language.)