Not terrible which is pretty damn impressive with this concept.

As a premise this does little for me as it's primarily surface level explanations designed to introduced high school kids to far more complicated subjects that can't be explained in a 10 minute video. Beyond that, it's still not good - John Green is prone to have bad, inaccurate framing for a lot of topics and this is often due to his own biases. I'll grant he's usually honest about his biases, but the more you learn about the world the more superficial and disingenuous Crash Course becomes.