Can you play in the hardcore/ironman mode (forget what they call it) and earn achievements while running mods?
It's stupid, I know, but I get a little thrill when that achievement window pops up; and as silly as it is, I'd probably take being able to earn achievements over UI improvements (even as much as they'd help.)
Yup, totally compatable! Its the only reason I have any achievements at all.
While playing on "Immortal" difficulty Achievements are unlocked
You are locked to the highest "difficulty" setting options of Classic
New difficulty menu gets unlocked. Going up to Tribulation IX with all difficulty settings enabled
Many in-game indicators disappear. Your knowledge of the game is tested to its limits
In Practice:
You need to enable Immortal for even the most basic achievements, like "1 creature killed". ie: a farm animal.
Immortal locks you out of multiple saves, though you can manually bypass this by backing up the save folder.
You cannot save manually in-game without exiting.
You cannot exit the game without saving (unless you use task manager to force close). If your game is autosaving, you have to wait for it to finish, then save and exit.
You cannot change the frequency of saves from every 20 minutes.
The already confusing Feng Shui system has some of its variables re-hidden.
Chances of success, eg: Breakthrough, Artifact Crafting, or GC Quality predictions are all gone. Easy to accidentally initiate a GC breakthrough instead of a normal one, panic, cancel it, and end up with a Tier 9 Golden Core Cultivator.
If you use the Developer Console during an Immortal game, you can no longer save as Immortal. Your old save is kept, but a new "effectively classic" one is branched off from it.
You can still use Mods, including cheat/admin mods like MODModifier (Mod), which is arguably easier than using the console.
Its important to know though that immortal mode is *more* then ironman though, notably it removes a ton of info that is critical for your first time playing the game.
If you don't already know how feng shui works then making working buildings is a big problem.
If you don't know what you need to have 100% breakthrough chance then its easy to mess up and fail your breakthroughs.
If you don't know exactly how strong your GC is and everything you need to do will be its easy to accidently get a trash one cause you forget crucial stuff.
I would very much not recommend it if you are just starting out as the game is already enough of a pain in the butt when you get all the info and can use saves, but achievements are indeed very shiny.