Writing the game's story

Almost every video game has a storyline behind it. Even a game that has neither cinematic features nor a single line of dialogue could still contain a background story that defines the world of the game. Oftentimes, video game storyline is parallel to the progression of the gameplay. The further away the player progresses, the more they will learn about the storyline of the game.

You don't necessarily need to present your game's story through narratives or cinematic features unless you're making a story-heavy game, such as Last of Us. For a simple game, it's better to let the players discover the background story themselves by playing through your game. This is much more rewarding than directly telling them everything!