Ark is about a guy who dropped out of high school and gave up gaming to make money for his ill mother's healthcare. He ends up making an account for a VRMMO and picking up gaming again to apply for a job in a game company. His progress in the game marks how well his application is received.
I suggest reading this and Legendary Moonlight Sculptor at the same time; they have the same translators anyway. It's almost like watching someone start to turn into Weed.
Comparing the main characters, Ark is something like a less exaggerated Weed. They're both desperate for money and greedy as a result but while Weed's penny pinching is a source of humor, Ark's can't really be laughed at. It's less of an omnipresent force. Weed's desperation drove him to become somewhat superhuman in terms of physical ability. Ark's physical strength is quite normal. Weed somehow manages to encounter famous people online and irl. He finds good teammates and while he sometimes journeys alone, it's usually by choice. Ark's online isolation seems more sensible given previous betrayals by teammates. Even Ark's irl relationships seem more natural than Weed's. A normal coworker, his mom's friend, etc. On the whole, Weed is funnier to watch but Ark is easier to relate to.
Weed is a funnier character to watch but Ark isn't derived of humor either. The job system is played for laughs. The survival cooking scenes are pretty funny. While Ark's irl situation is worse than Weed's, he concentrates on making the best of his time so some of his game adventures can be quite light hearted.
The VR aspect is explored pretty well in both games. In LMS the interplay of reality and game is explored better than in Ark but Ark is more creative in his thinking and abuses the VR system better in battle.
It's pretty early in the series so things can change but for now I'd recommend it.
This turned into a comparative essay. Good job self.
TL;DR: IT'S A SLIGHTLY MORE SERIOUS LMS. GIVE IT A READ IF YOU LIKE LMS/MMO SERIES.