1. There is very little story happening and, in particular, no actual "plot". You know your task from the beginning, there are no twists or turns, it's a "job" rather than a "quest".

2. There is no actual protagonist around whom such a plot could evolve. The player is an invisible background-persona like the "commander" in RTS games.

3. There is little "adventure". Player/IMPs/Mercs do what they do for money, they have no personal stake in what goes down other than risking their lives [which is part of their job]. Only for the NPCs there is an "open end" for the story, the mercs will return from their mission and resume their actual lives; from their perspective the events of the game are episodic and, ultimately, without consequence.