In the second episode, they joke about how Human Resources was "pitched" as The Office meets Big Mouth. In that context, I see what they were going for, and some of it works fine, but it definitely misses just as much. I'll say that the show matures into itself well, and by the end I'd definitely be up for a second season, but it makes some odd choices along the way. I'm really glad, though, that we're still seeing what's happening on Earth a little. The creatures are a really fun gimmick, but by themselves they don't quite work, and that shows. Connie and Maury, in particular, are really fun comic relief in Big Mouth, but Human Resources has to work to keep them interesting, and I wouldn't mind if they dipped out a little more in the future.
On the other hand, the rest of the cast are a lot more interesting. I actually quite enjoyed the Love Bugs this time around, and the entirely new characters of Pete the Logic Rock and Dante the Addiction Angel (brilliantly voiced by Hugh Jackman) are some of my favourites the team has come up with, and Petra the Ambition Gremlin is solid too. Our main focus, Emmy, is a little less interesting, but like many sitcom "stars", she falls into the trope of having to be a bit bland to make the story make sense, so that's fine. Plus, I thought the way they built out this world was just done well, creating a really fun setting. Joe and Gil, the new hormone monsters, I found less interesting, and kinda wish they weren't included at all, though there are some moments that work.
Still, providing a setting to explore more adult themes for the creatures, as well as giving us a greater view on their own trials and tribulations, ended up being a much more interesting show than I had expected. I thought the new humans were all written well, and the subjects tackled were given enough time to make sense, though this is clearly less of a focus (and therefore less well balanced) than with Big Mouth. But because the show is honest about that, it works, and by the finale I was really enjoying myself.