Re: punishment sex vs reward sex discussion (discussion)
Interesting question! I'm generally leaning toward reward sex, although I have absolutely no interest in being the aggressor; games where you attack people to rape them are big no-no in my book and I want nothing to do with those (which unfortunately is the majority of h strategy games premise

).
I'm definitively more interested in the gameplay element than the h element: Most of my favorite h-game have little in term of h-content (Like Nightmare Sphere). If there's no interesting gameplay, then the game holds little attraction for me, no matter how good the h-scenes may be.
However, there's two h-game that I found to be spectacular and which the inclusion of h-content makes them better games. I consider those to be perfect examples of what an h-game should be. One of those fall under reward sex, the other under punishment sex.
1) Pregnant Brave. I'm not a fan of pregnancy, but the concept works very well here as reward sex while being on the "good" side. It's a very decent strategy game, where the main character can birth various creature and unit types in battle. Every storyline stage, if your main character is defeated (you have a skill that brings you down to 1hp), you get an h-scene, your character can now summon that unit type, she gets back to full hit points and she turns into "awakened mode" (stronger) for the rest of the stage. If you get defeated while in awakened mode, you get a game over.
Basically, this means that you have play well to get finished off by the creature type you want to get both the unit and the h-scene from that stage, while actually winning the stage afterward. The h-scene are a reward for playing the game well, you are still on the "good guys" side, you are not an aggressor and makes complete sense from a story perspective. From a gameplay perspective, it makes you careful choose which unit you want to get (you won't have all of them by game's end) and it gives you a wide selection of units to summon during battle which makes you adapt every battle. Excellent showcase of a "reward" game done well, in my opinion.
2) Maidensnow Eve. It's an amazing roguelike game; the most enjoyable I've ever played. Without the h-elements, it's a great game... But the h-elemements push it toward one of the best games I've ever played period.
In short, while you also have your regular hit point bar, it's not the only element present. It's turn-based, it's challenging, and it's thrilling. Your character might end up knocked down, or ensnared by tentacles. The next turn, you might end up with your underwear being shifted or removed; you know what's comming next. When you end up in a bad situation, every turn really counts and every decision is critical. For example, I once ended up in a situation with half-hit point bar, half filled pleasure bar, with a tentacle in the mouth and two monsters on each side. It's my turn. I have a teleport scroll, but I can't cast it because of the tentacle in the mouth. Gamble and throw an holy water; the tentacle monster dies. The two monsters bring the pleasure bar to 80%. Read the scroll, get teleported a few squares away, get teleported near a few other monsters but barely manage to dispatch them. Immense sense of relief and satisfaction at evading disaster.
Not only that, but each piece of equipment have resistance bonuses (or penalities) for sexual attacks. For example, that bunny suit might give you a big boost to dexterity, combat bonuses and look sexy, but it also has fewer layers for enemies to peel off first and has low sexual attack resistance. It's something to keep in mind while gearing up your character.
Also, it's not GOR. Losing means that every enemy neary gets chance with you until they get enough eventually leave. Everything that happens to your character is noted down in detail; your character might develop bad traits or addictions depending on what happened. There's a consequence for losing (especially if you lose while there's a horde of monsters around...), but the game goes on. It makes losing far more horrifying than just a game over; there's consequences. I did a "no reset" playthrough of the game, and it was one of the best gaming experience I ever had (Finished in a good state, but there's been some losses...)
That's the kind of thing that's impossible without the h-part: The unfortunate thing is that there's extremely few h-games that take advantage of that. Dungeon and Prisoner looks to be extremely promising for that reason: It has both punishment sex ala Maidensnow Eve, but it also has reward sex (waves Miene x Lynn flag forever) if you do well.