Lust Grimm/YMMV

Alternate Character Interpretation: Most of the player character's dialogue and thoughts aren't revealed and can only be inferred by looking at the reactions of others. As a result, there's considerable leeway in interpreting their personality and actions.
Angst? What Angst?: This is par for the course for such stories, but waking up to find yourself in an alternate world filled with succubi who want to rape you really should produce more of a reaction than it does.
Disc One Nuke:
- The Paralyze skill has a chance of paralysing the enemy, preventing them from acting for a few turns. You can get it when you reach the Hades Coast, where the enemies (Sea Succubi) will initially be much higher level than you. However, Sea Succubi are weak to paralysis, meaning that the skill will always work. You can therefore defeat them much earlier than you should, rapidly gaining levels and money.
- The Embrace skill. It does minor damage and inflicts a wide variety of status ailments on the enemy. It always inflicts stat debuffs and often inflicts an ailment that temporarily prevents the enemy from acting (such as paralysis). If you use it again, the debuffs stack. Even bosses aren't immune.
Evil Is Sexy: The villains are horny, Stripperiffically-dressed succubi. Do the math.
Genius Bonus: You wouldn't expect a H-game to contain frequent references to the Brothers Grimm and their works. Those who are familiar with the Grimms will figure out Emilyn's and Herman's true identities early on.
Scrappy Level: The Underground Library. To get to the next boss, you need the key to their office, which is fair enough. But that key is locked behind four sets of doors, requiring you to find four keys in the library. Finding the keys is a laborious task - they're among the items found on the bookshelves, which are also filled with worthless book items, and (unless you consult a guide) you'll have to check them one by one. The rest of the level design only worsens the tedium, as it's filled with identical bookshelves and numerous enemies, and there is neither a Record Fairy nor a teleportation circle (unlike every other dungeon).
That One Boss: The Sheep Sisters. On their third turn, they use an unavoidable hold (unless suffering from a status ailment that prevents action) on you and get sixteen free hits. Unless you're massively overlevelled and/or are on Easy Mode, this will kill you. You need to use the Endure: Breast skill to survive the onslaught, and even then you need to struggle out of the hold afterwards. If you're repeating this fight (e.g. to get the unique drop), you'll be experiencing this every single time.