Any thoughts on how to make it more challenging? The quality of her participation in lessons (her "diligence") just affects how many lessons are needed to increase her ranking. Refusing a lesson entirely and needing punishment is presumably not what you have in mind.
Time pressure is only felt at the start of a game where you have limited budget. Without time pressure, even very inefficient gameplay (wasting time or money) is viable, it just takes longer. We could look at tweaking the game economy to make it harder to gain and keep large sums of money, or introducing other forms of time pressure that carry strong penalties for missing the deadline (for example, mandatory instead of optional guild contracts until you attain at least B+ guild ranking, with penalties if you fail to take a contract within a few days after turning in the previous one, and a demotion in guild rank [or expulsion from the guild at F- rank] if you fail to deliver on time, instead of the current situation where you are simply paid nothing if you are late).
First I gotta say I like the changes in 2.2! You guys are doing a great job with this game.
I'm not sure with messing with the game economy is the answer or introducing penalties for lateness. If someone is having a too easy time training the slaves, that's not going to make it more challenging for those players. It will only punish the players that are already struggling. My problem is it's too easy to train the slaves with the same cookie-cutter strategy that ignores so many of the game mechanics. Given its hardcore mode, it feels like this should be a bit harder to do.
It seems like the whole 'stick' aspect of the game is a bit neglected. I'm generally using 1 or 2 punishments max in total. Compare that to 1-2 rewards every day from day 2 onwards. I also don't bother with the rules until fear decreases to 0. They tank mood. For clothes, I just equip a sundress and slippers the whole time. I'm too lazy to micromanage outfits and mood is so important it doesn't make that much of a difference. I just spam the 2-5$ classes, auto-cast the rewards amplification spell, and get a 5* reward every day. Your slave automatically will become obedient and eventually devoted if you do this.
Some personal suggestions to make the game harder/more interactive:
Perhaps raise spoiling if your non-devoted disobedient slave is given comfy clothes right of the bat?
Make the optimal balance between punishment and rewards better somehow. My slaves are having such a cushy ride, and given the game's thematics, it doesn't seem right. "Carrot and stick" right? ATM punishing your slave really has only downsides, after you have raised a bit of fear in the first day or 2. Pride is easier to reduce later with other means. Maybe in hardcore mode, have spoiling raise every turn your non-devoted and disobedient slave has not been pushed outside of her comfort zone and has required to have been punished? There are lots of ways you could play around with the game mechanics to make punishment a more important part of the game.
I think it was better when you had to implement rules, regardless of fear. At least in hardcore mode.
IMO make mood less important for your slave's working results. It's a bit silly for me that even a completely disobedient slave with 9 red buds will still perform well in class as long as she is 'pleased', and earn a big reward. Meanwhile, if you put the fear of god into her with horrendous tortures, she will still perform relatively badly if she is not 'pleased'. If it is was necessary to implement rules, punishments, and BDSM clothing for your slave, it would be much harder for your slave to remain 'pleased' at all times. Having a very low mood has other drawbacks anyway, such as raising despair, so you would still be incentivised to keep mood above depressed, even if the mood had a lower impact on performance, relative to fear/obedience, etc. It doesn't seem right that it's optimal for my slave to be permanently 'pleased' from the very beginning! This is Rome!
Habitat/taming/awareness. A lot of effort has been made to make these interesting game mechanics, but currently, they can be ignored as they just rise themselves with no interaction. Within about 10 days I have 3-4 of each just by sending my slave to class and using rewards. Maybe make the specific clothes/rules/punishments that raise these more important, relative to whatever is making them raise automatically.
I got more thoughts, but that's probably enough for now!