The Moon Is Too Prestigious For Me
After playing NimbleBit's Bit City for just over a month, I've finally completed the game, or at least by my personal definition of fully populating Apollo City, the sixteenth and final level of the game. I'm partially writing this post as an update for my progress on the game, but also as a bit of a review for the Moon stage of the game, since I feel like it's a bit different from the rest.
In Bit City you build a city until it's completely populated, and then you move on to the next city which is larger. This repeats until you reach City 8, as City 9 has the exact same layout as Level 1 but on the moon! You still earn the same amount of money, but everything costs 1,000 times more than it does on Earth, so the progression is painfully slower (for reference, before my first prestige I was earning just over 50 million coins a second, but lots cost tens of billions). This really surprised me when I first upgraded, and after 2 days of extremely slow progress I decided to prestige partway through City 12.
The way the prestige mechanic works in idle games, including Bit City, is that you restart your progress back to the beginning but you gain an advantage that remains for the entire game, which in the case of Bit City are keys that provide a +1% earnings boost each. I already had 52 keys previously, and after my first prestige it went up to a 5,470% boost.
With this boost I was able to make more progress, but it was still quite slow for later stages, so I then prestiged again near the end of City 13 and got to a +19,510% boost, and again near the end of City 15 (+79,960%), then again in a lower city for no apparent reason (+80,510%), and then I prestiged one final time around two-thirds into City 16 into exactly a +200,000% boost (well, not exactly, I prestiged a bit lower and slowly climbed up to that round number since I found it satisfying lol).

Anyways, after getting the +200,000% boost I felt good enough about finishing the game this way! I did this last Friday (July 24), and after 6 days of playing on and off I fully populated Apollo City! I also completed all of the missions (which I did not know were limited, I wish they weren't).
At this point the only thing I could do in the game is prestige and return to Level 1. I could definitely try to go for all of the game upgrades, but that would take a long time on its own and I think I want to take a break from the game for now.

Now that I've spent more time in the game I can give some more concrete thoughts on it than previously.
I really like Bit City, though it definitely becomes a bit of a chore in the Moon levels, as you're essentially obligated to prestige over and over again to make any real progress. Admittedly it is very satisfying to prestige, as you can just rush through all of the first levels very quickly (at +200,000% I can finish Levels 1–8 in under an hour and a half), and it's a more long-term version of the satisfaction of "number go up" for me, which is ultimately what idle games are for. It's definitely more fun if you have a lot of time and/or patience, or if you have the ability to AFK the game (like me), but that also applies to any idle game.
In the end it isn't that much different from other idle/clicker games, and I'm not as into it as NimbleBit's other titles, but it still has a lot of charm that pulls me in, so I can still recommend it if you're into this type of game!