Any bored days analysts among us? I think it would be interesting to see a 2 month rolling trend (ie how does Jul + aug compare to aug + SEP compare to separate + Oct)
September is anonymously low in it's player counts because it never got that end of month patch like months across the summer did. Then October got an early month patch and November will have the same. So the numbers in September shouldn't be as low as they are, the the peak for November should be the peak for October in old money. Basically - I think the change in patch release month means months are no longer directly comparable. 2 month rolling may help paint a better picture of how player numbers are changing (or not as the case may be).
The reviews are more interesting as a shift at the moment.
@stealth_nsk may be onto something with the lack of sales, so there are less reluctant trier's giving it poor reviewers after expected disappointment. But I think the map gen changes in the last patch were a genuine improvement that seems to have fixed one of the most obvious weaknesses of the game. It's interesting that in spite of those reviews ticking upwards, player retention doesn't seem to be ticking upwards, unless you compare against September (which as mentioned, I think is giving a false impression based on our current measures)
Suspect this next patch could have an even larger peak than October, but the drop off is going to be interesting to watch - as peaks get higher, can the troughs also get higher?
The good news for the future of the game seems to be that a lot of people are still hanging about waiting on, to quote what I frequently see on Reddit and Facebook, the full game finally being released. The bad news for the short term seems to be that it still isn't scratching the itch for the majority of past Civ players enough to pick up sales and retain players beyond the established baseline.