1. Cartoonish body proportions or physically impossible large penis.
2. Creeper/Excessively Perverted MC. Even MCs who are relatively normal on this front still have peeping/spying on women in the shower scenes that are unnecessary and creepy, at least a lot of devs include an option to not do this, but still idk why its even a thing in so many games.
3. MC with zero interesting or special qualities who magically gets all women, usually for no reason or a silly reason like "his cock was so big they all became mesmerized when they saw it". Or the classic "MC somehow has a magical power which corrupts every female's mind to fall for him". Its just lazy writing.
4. Ren'py MCs that all look exactly the same, even have the exact same haircut. Also ugly MCs, can't get behind someone who is disturbing looking, it ruins the mood of the game.
5. Tedious RPGM games. RPGM is pretty bad in general, its slow and usually very tedious to use, but often these games have no logical or gameplay reason for being RPGM or having you do repetitive tasks in RPGM that take forever. Why make a slice of life game RPGM?
6. Games that only revolve around corruption, mostly RPGM. RPGM could be used effectively for games that involve medieval combat, but almost every RPGM game seems to revolve around a psychopath MC trying to rape a bunch of women, or a female MC getting raped and corrupted by everyone. Almost always, these games have no good/pure route available either. Its disappointing because RPGM while not perfect, still has potential to be used for interesting medieval stories or other themes involving combat and ranking up in order to progress with the story.
7. Beta MC v Chad MC dichotomy. Most MCs seem to either be ridiculously perfect or ridiculously pathetic. A loser MC who gets beat up every time he leaves his house and is always groveling or a chad MC who everyone on earth worships and can do no wrong. Is it really so difficult to just write characters with more depth? And if the character is weak can they at least have the spine to stand up for themselves? They don't even have to win fights but they at least should have the self respect to not tolerate abuse willingly, or they should have character development and grow a spine gradually.
8. Characters who are unnaturally forgiving or nice to a fault. Its ok for a character's personality to be nice, but so many characters seem to have an unhuman level of forgiveness and passiveness about things that would realistically make anyone angry. For example, when a character finds out they are being cheated on they will either not get mad or forgive the person cheating on them after a couple lines of dialogue.
9. Games with grinding systems for no reason. If you are trying to rank up for some reason in the story I could see the logic (specifically combat) but many games force you to repeat the same actions hundreds of times just to unlock scenes. IMO this is usually because there is very little content and this merely exists to extend the runtime of the game, still it is annoying and unnecessary. Add more dialogue or if its not a story-focused game, then there should be no need for such a system anyway.
10. Puzzles in a game. They should at least be rare and optional, if you are invested in a story then having to spend a bunch of time solving a stupid puzzle can be frustrating.
11. "Romance" games that have one kissing scene or something minor but somehow count as "romance".
12. Every character besides MC and LIs being unnaturally rude or hostile. Seems like every side character in games always seems to just be a pervert trying to molest a female character or a douche who is looking for a fight for no reason.
13. Games that don't have an option to skip/speed through dialogue. This is especially a problem in RPGM, but having to sit through some dialogue that is tedious or that you've seen before (say, if you're replaying a game to go an alt route) is annoying.
14. Antiheroes or antagonists that are just perverted. Antiheroes can be a very cool change of pace from the vanilla characters but so often when a character is evil or disturbed in some way which gives them a questionable morality, they are just excessively perverted. No interesting depth, they're just immoral because they're obsessed with sex... A good example of a great antihero by contrast would be the protagonist of The Devil on G-String, Azai Kyousuke. Maou from the same game also makes an excellent antagonist who is more interesting than "I wanna get all the girls".
15. (Mostly with Japanese VNs) Annoying tsunderes that do nothing but degrade people and physically assault them.