This is a Note to people playing the Demo thinking of upgrading to the Patrion version.
Various Features have been permanently removed or changed, this includes the hit feedback/stagger/collapse upon taking damage or having your HP fully depleted, the grabbling/seduction minigame, all NPC initiated sex, including grab and defeat sex and the game over CGs as part of the gameplay.
What replaced them, In regards to feedback, taking damage does not have any sort of feedback, but a short window of invincibility. Sex animations are unchanged, but no longer accessed in the game's core gameplay, rather they are now initiated by the player outside of combat by interacted with unconscious enemies when there are no conscious enemies near by, this is accompanied by a new animation to initiate sex, Fainting upon defeat has been replaced by a reused animation where Kincade is teleported away disappearing. Nothing replaced the game over CGs, instead your screen goes black for a moment and you restart. CGs are no longer accessible in gameplay and can only be viewed from the main menu after defeating and initiating sex with the enemy it relates to.
Some other changes include a significantly zoomed out camera and smaller Hud, the option to Zoom in and out during Sex, however Zooming in during sex still leaves it significantly zoomed out compared to the demo.
Over all effect on gameplay, Despite the camera being zoomed out so much most enemies still detect and attack from the same range so instead of ranged units attacking from just inside the edge of the screen, you can see them much further away and they will only attack once there they are about the same distance Kincaid is from the edge of the screen in the opposite direction she is facing, however some enemies like bomb throwers will attack from offscreen they probably don't reach you unless your below them.
The removal of the Stun and Grapple/seduction Minigame had made the game significantly less forgiving as enemies will no longer switch behavior to attempt to grapple, and will continue to attack, ignoring the fact that you are completely safe well grappling or having sex in the demo, the window of invincibility after recovering from a stun, escaping a grapple or finishing having sex is much larger, then the small window of invincibility you get after taking damage in the Patrion versions and enemies will continue to attack after taking damage, as such your way more prone to taking damage and get hit more in a shorter period making it much easier to die and die quickly, as compared to the Demo where you are often limited to only taking single hits in most fights, you can take avenge of the grappling system to avoid being targeted or swarmed by enemies de-agro and resume their patrol paths well you are in a contested grapple, allowing you let groups of enemies leave so you can evade or deal with one one at a time, additionally when escaping or ending a grapple or sexual encounter enemies will de-agro for long enough to kill most, you also get a window of invincibility upon escaping or a larger one after having sex witch is usually long enough to kill everything nearby.
In regards to gameplay feel, the demo gives more feedback and feels better withe the grappling system and game over screens, well the newer versions feel worse with out grappling and the black screen and restart on death feels incomplete.
As for the actual fetish niche, the Demo appeals to those who like to be dominated, the newer versions is made to appeal to to those who want to dominate others, witch ultimately may be your deciding factor.