It depends on your definition of ntr and also what is "skill issue" in this context. To illustrate,
Mirage Deflection is a good game and ntr is technically avoidable, but it boils down to dialogue choices. The choices are literally "Submit" or "Refuse", so I don't think much skill is required to figure this one out lol
For me, skill issue comes from mechanically complex games like Dark Souls so that's what I look for here, games that have some form of gameplay/combat, where you protect or try to save a damsel in distress.
Spider and Butterfly that was rec on the 1st page was a decent one, and I rec both Seed of the Deads, and
Shin Sei Den are neat ones as well.