Gene Rain is an action-packed game set in a dystopian world where three forces are fighting to end conflicts that have taken over the world. The game follows the story of three main characters, Alex, Salman, and Li Ying, who are on a mission to bring peace to the world. The game has a simple upgrading system that includes upgrading weapons and character attributes. There are four types of scenes in the game, including destroyed cities, quiet towns, deep canyons, and cities in the dark night, with more than 12 types of enemies, each with unique attributes and behavior. The game's AI has human-like characteristics, making the gameplay even more realistic.

The game takes place in the year 2100, where humans have abandoned the Common Era and established Gene Rain as the first year of an era. After twenty years of Gene Rain, the drawbacks of gene sequencing have come to emerge, and unknown creatures have entered the human world. The game's background story is compelling and adds depth to the gameplay. Overall, Gene Rain is an exciting and thrilling action game that will keep players engaged for hours.