This is a really well-thought-out mechanic with just the right amount of additional functionality to keep it interesting and varied. :D
I would've loved some sort of visualization for the correct timing (at least in the beginning) to prevent confusion when momentum is lost on a bad input. But that's just me. I get anxious in timing-based action chaining when I don't have feedback (visual or auditory) for the correct timing.
It's amazingly complete and polished, btw. Respect!