Very clear, well spoken and easy to understand. It gave me a sort of educational lecture/presentation vibe. (If you want it to be more conversational, I think you could easily use a less slow and measured style and still be perfectly easy to understand)
Sound quality: A
Clean and clear audio. If anything just a little too clear, in that I occasionally felt like there was a little too much "mouth noise". But Ive very susceptible to noticing that and even then it was nowhere near a level Id find unpleasant.
I felt like you were having trouble deciding what knowledge level audience you wanted to target, and it got you into a bit of trouble. The information itself was fine, but some of the level of explanation seemed inconsistent. For example, you explained that "the moon's orbital period (its year), is the same its its rotation (its day)", but later you throw out "Keppler was able to figure out" without any mention of who Keppler is. Although it might actually be my problem rather than yours, since I knew most of that information anyway so Im only guessing at what the intended audience would think too. I just felt it was a bit strange.
Cant speak for anyone else, but I like the idea and the audience participation. I also found the puzzler straightforward enough to be easy to start thinking about, while still being an interesting enough question to be fun to think about.
Other note: I like the music, but the intro music seemed slightly long. It got me in a listening mood, but I was ready and waiting for the content to start for a while before the music finished.