The hard part is the transition from beating people up to lewd. If you intentionally go for the lewd route from the start carefully avoiding training martial skills, the first boss is not had with lewd, not even on hard difficulty. You can get through the first level without lewd but later it becomes harder to avoid. You are probably hitting the transition from not lewd to lewd by the first boss. This said, I think it is the most fun part of the game for me when Karryn makes all of her sexual discoveries. Later levels it gets a bit repetitive.Actually, I took my time in my first save to enjoy the lewd stuff and spent time grinding for combat. Once I reached the pig boss it turns out it's way harder to beat him if your slut level is already high enough to have the good sex stuff unlocked.