This game is as close to a gold standard of H-games as can be within reasonable production cost.
First, it is a game. You have to play it to get results beyond some defeat scenes -- and you have to be good at it to get the results you aim for (whichever these are). Which leads to
Second, this game is diverse. You can maintain your purity and play it as JRPG game to win through combat, you can manage the prison into the safe (or unsafe, if it helps advancing your goal) zone, you can fuck the prison into submission. Neither of which will be a walk in the park. Leading to
Third, this game is rather complex. To succeed, you will have to balance your training against prison management on strategic level, your mental state versus your buffs on tactical, all while beating up (or fucking) 'enemies' and watching your vital resources. Also, there's fatigue and sexual anxiety, each of which that can turn even the fiercest warrior into a rag. And resting has its own risks and cost. This provides for diverse experience and replayability.
The game itself is masterfully crafted with no stuff feeling out of place.
It has simply the best battlefuck in the genre to this date.
The story is fun and surprisingly solid, especially for the genre.
Combat is dynamic enough with lots of choices and interactions.
Art is very good if huge tits are your thing.
Sex scenes are also good and quite diverse for different situations. Some of those also depend on you being active or passive.
Voice acting is very good.
Corruption mechanics is very naturally intertwined into the gameplay.
Also, the game is actually well balanced in difficulty.
Plus, if you are done completing the game, there are user-made mods to renew your experience with different settings, pregnancy, cheats, etc. Mind that some of them (CC mod, specifically) can break one aspect of the game if you're getting ahead of yourself in that regard.
All in all, it is a jewel worth digging for, one of a very few ones (and I've seen many H-games, in the high dosens or low hundreds). It can be praised for most of its aspects -- with ease.
Of course, there are some downsides as well.
The animated cut-ins are on the simpler side.
Big animations are few and far between (can't actually remember anything except riding as a top).
Karyn talks a lot more that I feel would be appropriate.
Status window messages are too short-lived and window is too limited in height to provide really useful action log.
Equipped starting title is an outright newbie trap. At least it can be changed right away.
Gym addon doesn't really add much content.
Levels 4 and 5 don't provide side activities (or anything meaningful) when subdued, most content and management decisions are concentrated on levels 1-3.
Also take note that that you also fight a timer, albeit very adjustable with your actions. You can extend your gameplay probably indefinitely, but you will have to take actions to do so and prevent key prison stats spiraling out of control. Also, riots, although not on a timer directly, constantly increase in probability until it reaches 100%.
And yes, developing Karyn takes time and effort -- but it's nowhere near some horrible unpleasant grinds that are out there. On the contrary, it takes just a few (ingame, obviously) days of combat or sex experience to hit the caps for any given level.