Brilliant Blossom Princess Prececile

1) Defeat Violation, and lots of it
Including parts where you control the male protagonist while the heroine is getting r*ped by the enemy. The heroine gets used until her purity is no more.

2) Transformation Cancelling
Most defeat events involve the transforming heroine's complete defeat,
resulting in her reverting to her human form.
Her magic power is squeezed out with bear hugs, energy drain, etc., leaving Sakura in utter despair.
Includes genres such as preg-belly, birthing, and de-aging.

3) NTR
Sakura is your childhood friend, but a whole cast of men and monster alike are waiting to have a go at her.

4) Exploration and Puzzle-solving
Search an open world that avoids railroading with objectives like "go here, and do this".
Check out suspicious place yourself, and solve puzzles with logic.
There are lots of hidden elements to be discovered!
Watch for walls to squeeze through, hidden paths, hidden items, and more! (Feel free to ignore these elements if it's a pain, too!)