I found the pregnancy content in this game to be pretty top notch. I dunno why you would expect it on the pure route though lol. It usually goes without saying if you want this kind of content you don't try to keep the player character a virgin. Though it is unintuitive that you need to lose before the monsters can do stuff to her.
If you beat the game, you get an automatic-win ability. I thought it'd be easier to clear the game with that when I'm intentionally losing; unlike the pure route where I can always win and am rewarded with experience points.
Also, the harem ending was more appealing to me, but it was only on the pure route. I was disappointed that there is only
a) a small chance of getting the girls pregnant for this ending
b) given that the ending crystal scene-viewer doesn't show that alteration, I doubt it changes much