From MangaHelpers:
29-year-old programmer Suzuki Ichirou finds himself transported into a fantasy RPG. Within the game, he's a 15-year-old named Satou. At first he thinks he's dreaming, but his experiences seem very real. Due to his use of a 3-time-use special power (meteor shower), he ends up wiping out an army of lizardmen and becoming very high level. He hides his level and plans to live peacefully and meet new people, though developments in the game story (like the return of a demon king) might get in his way.

The spaceship which Imperial Galactic Navy Officer Alan Corinth helmed was shot down by a surprise attack during hyper-space navigation.
Completely due to freak coincidence, Alan became the only one in the ship to survive.
The severely damaged spaceship lost its navigation capabilities and plummeted onto a nearby planet.

Using an escape pod, Alan headed toward the planet alone.
Thus began Alan’s quest for survival on the underdeveloped planet utilizing the symbiotic nanomachines [Nanom] within his body.
Surprisingly, the planet was home to a thriving human civilization whose genetic code closely resembled Alan’s own.
Even while remaining at a loss due to being thrown into a world of swords and magic, he tries to live as best he could together with his newfound comrades.

What would Alan achieve this strange world?

The Sci-fi Fantasy story in a Medieval setting now begins!

The manga will focus on the character Koharu Hidaka, who is a middle school teacher close to 30 years old in 2007.

[Adapted from one of the old top novels of all time!]
God created the Abyss to escape his boredom. Trapped in the hellish Abyss, humanity was on the path to the apocalypse… “Is it over for us… now…” On the brink of humanity’s annihilation, the four strongest survivors tried to prevent it by traveling back in time to the point just before humanity was pulled into the Abyss. But only one of them could go back to the past. “What’s there to think about? Isn’t it already decided who’s going? The strongest among us, Kang Hansoo.” This is the story of the life of the legendary powerhouse, Kang Hansoo, who returned to save humanity from its doom. Will he be able to save everyone?

The manga centers on Poro, a demon from the underworld who comes to the human world.

The ordinary salaryman Park Do-hyuk, finally got the
awakening he had always wished for in a life or death situation!
Unbelievably, the memories and experiences from the game he spent
his entire life in his twenties playing became these powers of awakening!
What’s more, it was a 1 in a billion ‘Triple Awakening’!
The player Park Do-hyuk’s journey picks up now,
as he aims to reach the world’s peak.

- This will be the complete webtoon adaptation of the popular web novel by the author 청초.

Hibino Ayumi: 27 years old, single, a completely average office lady. But in her free time, she turns into a SOLO CLIMBER GIRL. Armed with plenty of delicious ingredients, she eats her way through the mountain trails, one by one.

Riku Mikami, who is starting as a university student in the spring, finds out that his favorite VTuber is taking a hiatus. The one who cheers him up is Rui Saionji, his classmate. Will Riku resolve to make Rui his "oshi"?

Kouta Takeda who just started working at XOX Corporation, meets his new boss, a beautiful woman with big breasts named Kyouko Takizawa.

Akira Kogure, an introverted loner high-school student befriends the student council president Shizuka Takasaki, who excels in both academics and athletics, blessed with beautiful looks from birth. Though their relationship may seem to be normal, both are keeping a secret that they can't reveal to anyone?!

There was an inn with an urban legend among adventurers. “The Inn that won't let you die if you stay there.”

Loretta arrives at the in as part of her quest. What is the secret of the “Deathless Inn?”

“Save Point.”

It was an inn ran by a maxed out adventurer with the ability to create “Save Points” who came from another world. He retired from being an adventurer and decided to run an inn, while training newbie adventurers. Loretta, who needs to become strong, will be trained by the innkeeper, Alexander.

If you die, don't worry about it, just hit load!

The Adresia empire on the Vogel continent. There is a battle over the throne of such an empire that possesses powerful military and vast territory.
With the successor undecided, the children of the emperor are vying to expand their power. However, there was one prince that everyone says will definitely not become the emperor.
The seventh prince, Arnold Lakes Adler. The young man who was inferior to his younger twin brother in every way, the dull prince.
Incompetent and lethargic, Arnold wastes everyday just playing around. However, behind the scenes, he is one of the only five SS-Class adventurers called ‘Silver’.
Seeing the intensifying battle for the throne he decided “I don’t want to die so let’s have my little brother become the emperor…”
This is the tale of absurd secret manoeuvres of the prince who is uninterested in the title of the emperor.

Yuta Uematsu is a aspiring novel writer who has long had feelings for his childhood friend Michiru Okuwa, who had always supported his creative work. He finally decided to confess his love to her, even though he didn't feel like he was a match for Michiru, the most popular girl at school. When Michiru brushed him off with the words, "It's impossible!" and stormed out, Yuta was left stunned in disbelief. Michiru went back to reading "Digital Masters," a very popular web novel. However, "Digital Masters" was actually Yuta's work....... This is a romantic comedy revolving around Yuta, who is actually a very successful writer, and his high school life.

At the risk of his own life, a young man sets foot in the ruins of a devastated old world. His name is Akira, and in order to claw his way out of the hellhole that is his birthplace of Slumtown, the boy became a hunter. In the wastelands he happens upon a strange woman, standing perfectly still, stark naked.
She is beautiful, but it seems that only he can see her. She exists incorporeal, tantalizingly beyond any touch, and she tells him her name is Alpha.
Alpha won’t show even a sliver of her real intentions, but with a wide smile, she brings Akira his first commission as a hunter. Akira takes the task, if only to become a stronger hunter, and having entered a contract, their dramatic lives in the hunting profession was set to begin.

From Stories of the Boy Hunter as recorded by the Eastern Hunters’ association.
Written post-collapse of scientific civilization.

He lost his new home and all his property, but found a cute girl!

Harold, a poor laborer who saved for years, finally obtained the house of his dreams, only to lose it to a fire the very same day. Feeling like nothing mattered anymore, Harold finds himself at an auction, where he ends up spending all of his savings on a slave, Atie...

Harold, with his secret technique, and Atie, with her skills as an adventurer, begin their freewheeling journey now!

Webnovel link: https://ncode.syosetu.com/n0884fk/

Unknown monsters have appeared on Earth, alongside ‘Superhumans’ who appear to dispatch them. With these mysterious monsters and superhumans, a new ‘Superhuman Era’ begins!

Asahi and her friend Yamato went together to an exclusive event as test players for a new game from the cellphone-game company "Sky Nova." The test players were a diverse lot of all ages, from ordinary teens like Asahi to popular idols. The company took all of them on a cruise to explain the rules of this island-based, treasure-hunting survival game. Suddenly, during the presentation, all of the participants lost consciousness. They woke up on an actual island wearing a strange watch with the words "Game Start." Now they are all stuck in this survival game, which has become all too real and deadly!

I don’t need any deep relationships. I have no desire for a girlfriend, and I only require one friend who holds any value to me. Ever since I threw out my youth for the sake of efficiency, there is one person who keeps entering the bedroom of Ooboshi Akiteru. She’s neither my little sister nor my friend. She’s nothing more than a bothersome, annoying Kouhai, as well as my friend’s little sister: Kohinata Iroha.

“Senpai, let’s go on a date~! Did you think I’d say that~?”

Rather than blood, it seems like energy drinks run through her veins. She keeps occupying my bed, and she tries her best to seduce me with whatever method she can play to her favor. She’s a girl who’s constantly annoying and obnoxious around me. Even though I’m busy all day long, she doesn’t care.

And in case you’re wondering why all these envious gazes are directed at me, it’s because Iroha is actually really popular. She’s an honor student at our school with top grades to boot, and she’s known for being kind and proper to anyone she meets.

…Hey now, why are you only so annoying when you’re around me?

In the final battle against the evil Exterminators, Asagaki Tougo, a power ranger, traded his life for the enemy's. It seemed like everything was over, but suddenly he found himself in another world! He becomes an adventurer, transforming into Kizuna Red, and continues fighting to save people in trouble! Here he meets a young Wizard named Idola and his journey in this new world begins!

From LHtranslation :

In a certain world, there was someone who excelled in magic combat, people called him 『Sage』. Seeking the strongest combat art, he devoted himself to research every magic and combat arts in existence. And the conclusion he arrived at was very cruel, 『My body is not fit for magic combat』. Yet he didn’t give up. He sealed his own soul with a magic art, and was reborn in a far-off future. And the magic theory in the completely changed world he saw there was of unbelievably low level.