It’s hard for designers not to repeats certain gameplay scenes in single player games. In fact it’s desirable to repeat some types of scenes. Imagine action movies without a car chase (More on that another time)! However, there is a big difference in repeating scenes because they are needed and repeating scenes because designers can’t think of anything else to add.
What gameplay scene has been over used the most in SP maps and mods?
Of course the headcrab answer only relates to Half-Life Universe maps and mods but since those games have the most SP maps and mods available it seemed fair to include it.
I actually don’t mind having headcrabs jump out at me while crawwling through air ducts, in fact I always expect it. What really annoys me is the large stash of health and ammo just before a big boss fight or a very difficult section. This gives me information about the coming level. For some this might add to the anticipation but not for me.