An update on my progress in Civ V.
Out of 173 achievements for the base game plus all of the DLC, it seems there is only one that is just too difficult for me: "All-Achieving Zeus" (win the Wonders of the Ancient World scenario on Deity [the hardest of all difficulty levels]). I did fine on my own until I got to Immortal (second hardest difficulty level). I searched the fan forums, Civfanatics.com, for helpful advice from other players. Although I was then able to easily pass the Immortal level thanks to what I read, I just couldn't seem to do the same on Deity. I've tried and failed three times over the past week, and that's not including all of the countless restarts I made, just for a favorable map arrangement. The problem I'm seeing now is that all of the strategies I've read online have one thing in common: "It takes a little bit of luck." If the deciding factor of whether or not a loss is guaranteed really does come down to luck, then I'm not even going to bother, since it will ultimately just be a big waste of time.
The other scenarios I've played on Deity (Mongols, Vikings, and Korea) were rather easy because they were all focused on combat, which is simply a matter of replenishing your armies and knowing where to put them. The other two scenarios (Conquest of the New World, and Polynesia) don't have achievements for higher difficulty levels, so I don't know how hard they can be. With this last scenario, Wonders of the Ancient World, I think I might have finally hit my difficulty limit. I just don't see how I can possibly get that last achievement without cheating a little bit. I do know of some ways to do just that, but I'll hold off on such attempts for now.
With that off the table, I now have only three achievements from the base game and DLC left to go (build 1000 temples, chop down 1000 forest tiles, and win 100 games). All of them should be very easy, but it will take a long time. I'll just have to play a bunch of quick and easy games to get those last three. Then I can finally take a long break from this game.