The Black Necromancer - Chapter 488 Battle Of Valeant

This novel is also known as Almighty Video Game Designer

Chen Mo a game designer got sent to a parallel world with advance technology but undeveloped game concepts.

Watch as he redefines the world’s gaming industry with the games he remade from his old world.

- Description from Novelupdates

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

Eli Turner had perfected the art of coasting through life, gaming, lounging, and vibing with no grand ambitions beyond the next high. But his laid-back existence is upended when his laptop inexplicably transforms into a gateway to another world. What starts as a surreal escape becomes a perilous journey as Eli finds himself wielding a mysterious system that allows him to level up, fight monsters, and gain abilities beyond his wildest dreams.At first, the portal world feels like a haven, offering purpose and adventure Eli never knew he craved. Guided, or manipulated, by Azrael, a mischievous god orchestrating the game, Eli rises as one of the system's chosen players. But as the quests grow more dangerous and Azrael’s true intentions begin to surface, Eli struggles to balance the fantasy world with his life back home. His girlfriend, Sara, and his friends are left grappling with a version of Eli they hardly recognize, as the lines between his two lives blur.When the system expands to players worldwide, Eli crosses paths with others drawn into Azrael’s cosmic experiment: Yumi Tanaka, a fiercely disciplined Japanese student with a perfectionist streak, and Arjun Mehta, a charming Indian playboy with secrets of his own. Each carries their own burdens and ambitions, but all three must face the harsh truth: Azrael’s game is far more than it seems.As alliances are forged, rivalries ignite, and the stakes escalate, Eli must confront not only the dangers of the portal world but the growing rift between the person he is and the hero he’s becoming. In a game where every move is a test and every choice ripples across both worlds, the question remains: can Eli, Yumi, and Arjun uncover the truth before the system consumes them all?