I highly recommend Subsurface Circular. It's a visual novel, yes, but quite loose in its structure. You engage in meaningful dialogue, solve problems and engage with a mystery. You are a robot detective on a subsurface train. A worker robot tells you about the disappearance of its friend. You begin to investigate the disappearance, despite not having official permission from your human overseers to do so. Through a series of interviews with the passengers on the train, you will begin to see the outlines of a conspiracy. It's a very good game and well worth the price.