These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Rune Factory 4
Demonic Spiders: Thunderbirds have an attack that shoots lightning bolts all around them, which comes out so fast it is impossible to fight them in melee without getting hit.
Disc One Nuke: A minor example for the first dungeon, Forte starts at roughly level 12 (Hardly surprising, given her profession) and she starts with the second tier long sword. She's also the only person you can ask to go adventuring with you immediately. Even the boss of the dungeon doesn't stand a chance against her, and she won't even take scratch damage until halfway through the second dungeon, even farther if you fill in her missing equipment slots.
Dude Looks Like a Lady: A complaint had about the male MC, which is ironic because Lest is the first male MC to be voiced by a guy in the JP version.
Goddamned Bats: Spiders, due to their web attack which slows you, making it hard to dodge other attacks, including the webs again.
Ho Yay: Quite a lot of it in this game compared to its predecessors, with one notable example being Doug and Dylas as stated below.
The eligible bachelors will complement the main character's cuteness, get flustered at the thought of spending time with the main character and get jealous when they're getting along so well with their current partner... even if the main character is Lest, the male main character.
During one of the boys' sleepovers, Leon suggests that next time, they should invite the girls, too. Lest claims they can have fun without girls, and Leon tells him to please be sure to sleep on the other side of the room.
Les Yay: The day before White Day, Illuminata tells you she's going to be participating like one of the guys and asks if that's a problem. If Frey gives her a cookie on White Day, she says she's always happy to accept one from a lady. Maybe her High-Class Glass goes back to really old lesbian stereotypes?
Margaret thinks Forte is really cool as a knight in shining armor, though she seems to treat her phrasing as more That Came Out Wrong than a demonstration of her preferences.
Saying that Pico is canonically in love with Dolce is easier than saying they're like sisters.
The Scrappy: Illuminata is not very well-liked among fans, due to her overconfidence and tendency to jump to conclusions as a self-proclaimed detective. It does not help that in one of the random events, she slaps Amber without apologizing later for taking flowers from the shop without permission.
Ship Tease: The game is more than happy to tease Doug/Dylas. Their competing and bickering is interspersed with veiled kind gestures (showing concern when the other is injured, or secretly giving each other birthday gifts) and multiple characters will comment on how fond of one another they are. Dolce even calls them lovers, much to their mutual horror.
It's also suggested that Leon likes to pick on Forte so much because he's basically a giant kindergartener pulling her hair.
That One Boss: Thunderbolt, who is impossiblyfast and strong, likes to spam lightning attacks, one of which shoots out in a dozen directions, and plays dead at one point, so that just when you think the fight is over, he jumps back up and probably gets a good hit on you. Fighting him without a healer or lots of healing potions is not recommended.
Thankfully, your allies aren't fooled and this gives you the hint that he's playing dead. They'll keep attacking him while he's down, something they won't do against anything after it's been killed. This would go into artificial stupidity if the situation was even slightly different in any way. Unfortunately, he gets more aggressive after he gets back up.
The Crystal Mammoth in Rune Prana is essentially the only obstacle in its segment of the dungeon, and deservedly so. It's significantly harder than even the Dual Boss of the next area.
That One Level: The Forest Of Beginnings. For starters, you are on your own for this stage, and to enter you have to destroy a large gate that summons random monsters and changes types frequently. Next you have to make it though 7 stages, each are blocked until you defeat the monster and invoke Checkpoint Starvation, this combined with the fact that you can't return to the clinic if you died (since you're on another plain of existence that requires a rare artifact to escape from or a rare magic that only earthmates can cast to rescue something form there) mean you have to run this gauntlet from the very beginning if you fail. The first three are easy if you know what you are doing, the 4th and 5th can ruin you if you're not careful, the 6th one is a Dual Boss between two statues that shoots Fire and Ice attacks in a pattern (one attacks after the other) make it difficult to focus on one and the last stage is Sarcophagus; a monster with Teleport Spam, a plethora of attacks that all hit hard and once he Turns Red, a barrier that deals damage if you are too close and could kill you even if you defeat the boss at the same time. All in all this would be the first blatant Difficulty Spike in the game.
The Woobie: Hoo boy. Most of the characters have some sort of tragic past, but Venti, the Guardians, and Doug take the cake. Venti is slowly dying from a lack of runes coming from the land, only being able to keep on living due to her four best friends sacrificing her humanity to maintain the rune population, thus keeping her alive. Once the protagonist defeats them, though...things go downhill quickly. The Guardians, as previously mentioned, pulled a Self-Sacrifice Scheme and turned themselves into monsters using the Etherlink spell to keep her alive. This froze them in time, being kept as monsters for centuries until they were beaten by Lest/Frey. All four of them show visible signs of missing their former lives, but Leon and Dolce arguably have the hardest time readjusting to the new time period. Doug is hiding some serious anger toward Ventuswill, being manipulated by the Sechs Empire into thinking that she leveled his village, killing his family and friends, when it was really the Sechs who did it. He tries to outright murder Ventuswill in the first arc, but only stops when she gives him a Kirk Summation on what he's doing. In the second arc, he nearly gets killed twice, first taking the bullet for Blossom after a Sechs Soldier attacks her, and trying to get the Rune Spheres back from Ethelberd the second time.