Savior of impregnation was a bad game, it wasn't because it was NTR or whatever but it was badly coded, with many mechanics that made 0 sense and that got abandoned later on and others that were simply broken/useless.
If he cared about the NTR aspect he would have just added a simple gameplay mechanic more worth it than what we got, this is personally how I would have designed it:
-Girls in the game having 3 stages; Love the MC, contested, Love the antagonist. Each of them having some effects:
*If a girl loves the MC she won't have sex with Bob, he will be trying to seduce her to have his way, on the other hand the MC only needs to advance her love quest (basically dates and sexual interactions with the girl) until a point in which she gets impregnated by the MC and is protected against Bob, not having to worry about it anymore.
*However if Bob manages to bed the girl we get to the contested stage, in this one we will have to put some effort in seducing back the girl and having sex with her to return her to stage 1, but Bob won't make it easy since he is good at sex.
*In stage 3 we will find ourselves in the same position as Bob at the start and entering a countdown for NTR, we will have to seduce the girl back before it's too late or Bob will end up impregnating her and the girl is lost.
In this setting you have a clear win condition and a clear defeat condition so players can end the NTR attempts from Bob while enjoying some gameplay, if winning you will frustrate Bob and get that extra satisfaction.
Overall we would have gotten some use for the MC dating skills that we learn from Bob at the start and we would have a more complete system.
And I say this simple system because it could have been just a simple improvement over how Bob worked in said game.
-Related to Netori it was the main focus of the game, however it was quite weak, I don't see much difference between non married girls and what we got in the game. Since I'm not a fan of it but not against it I won't say much about it.
To end: Personally I enjoy avoidable NTR games, if I have a fetish it is to frustrate and defeat antagonists, for that we need a challenging antagonist and a good enough MC and previous game was OK, not great but at least we don't get a tiny dicked protagonist that gets humilliated by it and ends up enjoying seeing his love interest get fucked which is 99% of NTR games.
What Savior of impregnation lacked was mainly a better game design, it suffered too many changes during development like the karma value and some other unused systems and since this game doesn't follow the spirit of the previous game I wouldn't have called it savior of impregnation 2, but that's just my opinion.
Either way if he makes a fun gameplay I will play this game, if not then it is kinda hard that the netori will attract me to play, I didn't play the tower of lust or whatever is called since I didn't like the concept, it's not a big deal.