Solid game with some notable flaws. I'll split them up a bit for clarity
Exploring:
1. Sometimes dialogue plays on a loop, no matter how many times it's been seen. This is particularly annoying with the ball rolling puzzle, because every time you exit a battle, the sound effects and conversation will play as if you just solved the puzzle.
2. Pickups are hard to distinguish from regular props. There's no way to tell at a glance if a book lying on a desk is one that will upgrade a skill or a useless one that doesn't do anything. The first time I played, I didn't end up grabbing healing items, resistance crystals, or empty bottles simply because I didn't know they were things I COULD grab. A soft glow or particle effect when the player is close would help these stand out more.
3. there's no way to tell when defeated enemies will get back up. this one is more an annoyance than a flaw, but I didn't even know they COULD get back up until I was coming back from the sewers and blindly stumbled into the first enemy. a timer of some kind would be nice to help remind and inform players would be appreciated.
Combat:
1. Some skills are just worthless without upgrades since they are missing the features that make them worth using. Sexy Dance and Masturbation are just a waste of an action point at level 1.
2. Priestess enemies are more annoying to fight than hard, especially in early game. Enemy healing is always annoying(something even joked about in-game) but while the healing is negligible late game, early game it just drags things out, especially if you don't have any upgrades for Spank. In my first playthrough, I got jumped by the lone level 5 priestess at level 2 and a FRUSTRATING amount of turns just ended up being me dealing 40 damage then her healing 40 damage.
3. You can lose a fight due to RNG, and that's not a great feeling. The arousal system works great with enemies, good risk reward of spending an action point to try and seduce an enemy with low arousal to possibly knock them out early is great. Less great is when an enemy just knocking you out at those low percentages. Adding a little minigame could help with that, maybe mashing the spacebar to resist the temptation. The higher your arousal, the more you need to mash with you just autolosing if you're at 100%. But it hardly matters since:
4. Losing is meaningless once you have Purification. Early, losing means you gain more corruption, ticking ever closer to 100 and a game over. But once you get Purification, the 10 you gain can be immediately canceled out by the 30 you can heal.
UI:
1. Some of the menus feel clunky and irritating to use. Not in any game-breaking or egregious way, but it's little things in combat like having to click the skill you want to use every time rather than the game remembering the last skill you used, or having to enter a mini pause screen to use the two exploration skills and the ACTUAL pause screen. There's also no way I can find to quit to the main menu mid-battle.
2. The gallery is just... kind of broken? If you open it straight after launching the game, everything is fine. But if you close and open it again, or open it after starting the main game, the layout and sizing break if the game is in full screen. Buttons are sized and positioned as if the game were in windowed mode, as are the animations themselves. Additionally, the Horny Water animation will just play repeatedly until you return to the main menu.
I hope this criticism doesn't discourage you, I enjoyed my time playing your game and think it's a solid foundation for a larger game if you want to do that. The art was good and the combat was satisfying when you had all the tools. If you ever want/need another playtester, I'm always happy to help. Game devs should help each other and all that.