"Immersive storylines" refers to narratives or plotlines that completely engage and absorb the audience, making them feel like they are a part of the story themselves. Full definition
Serious games feature immersive storylines, memorable eLearning characters, and game mechanics. (elearningindustry.com)
Hellblade: Senua's Sacrifice Review, the game brings a distinctive dark world of protagonist Senua, Ninja Theory has added some serious Hack and Slash combat system with immersive storyline and touch of chaos. (gamepur.com)
The other letdown is that despite the added features, the improved locales and graphics, the more immersive storyline and varied mission styles, you'll still get to a point where you realise that it's all just more of the same thing. (impulsegamer.com)