Thank you for sharing your impressive work!
A few thoughts and suggestions for you.
The idea of a Doorway as the entry point to relevant, specialized information in an overwhelming sea of loosely related information should make sense at first glance.
To help that idea really come across, I suggest that future videos or other explanations make a tiny modification in describing the metaphor.
A 'doorway' is a noun, a stand alone object. I would modify your use of the word ever so slightly by describing it as: A Doorway to related (or relevant or selected or curated or specialized ) content \ material.
This slightly fuller description completes the picture in the new user's mind. It helps to convey the idea that the imaginary symbolic object you've conjured on top of a whole bunch of other visual objects sitting right in front of them on the screen (more on that below) is purposeful as a conveyance.
Extending the metaphor a bit, you might use language such as: "To metaphorically use the Doorway to access Climate Change information most relevant to you, just click on a curated topic. And then on any other topic linked to that topic. And so on."
The Overwhelming Visual
You have gathered so much wonderful information. The initial presentation of all those thoughts and links to the first-time or casual user may be quite overwhelming (read: off-putting).
Suggestion: Address, in your video, this fact directly. You might say something to this effect:
When you first see the volume of topics and links we've assembled for you, it may appear a bit overwhelming. But the beauty of this system is how accessible and navigable all this information is! The information is organized, tagged, and related in a very special way so that you can find information you might not otherwise, and find information you want to find exceptionally fast.
Or something to that effect. And then present the great overview demo that you have already prepared.
Hope this is helpful.
Many thanks for putting The Brain to work in this way and sharing your efforts with us here.