I find my brain extremely happy when a game provides ample opportunity to make connections, like in Dwarf Fortress, where I watch an event unfold, which can stir my creativity and imagination like nothing else. Writing a story out of it is extremely smooth and easy compared to other sandbox games.
I also find myself in love with immersive sims like Desu Ex and Thief, where level design and exploration take a front seat, every map is like a big playground with verticality and branching paths, where you find secrets and lore hidden around every corner in an atmospheric world.
What is immersion to you?
Nothing takes me out of immersion more than pointless exposition. Stop talking to me, the player, and keep the conversation normal for my character.
Probably why I love soulslikes, especially the mainstays by From. They only give you terms of the world and don’t explain anything to you because you are part of that world and should know this shit.