does Agent = Easy, Special Agent = Normal, Perfect = Hard? Agent's super easy. Only thing that kills me are turrets that catch me off guard.
The shooting mechanics are kinda hilarious, since auto-aim magnetically drifts to enemies so easily, but I think the level design is better than most FPS I've played over the past 10 years. It isn't a straight corridor (or curvy corridor for the illusion of openness) and it isn't too confusing so that you need radars and bread trails to get you to your objective.