So I had an idea; what if there was a counter that showcased the number of a type of kill you got?
Just something in your passive stat listings that would have stuff such as:
Window kills (where you throw someone through a window to kill them):
7
Grapple kills (where you use one of the preset equipped buttons to perform a kill with jason's bare hands):
15
Weapon kills (where you just swing your weapon and kill someone):
3
Weapon grapple kills (using your assigned weapon grapple kills):
8
And so on for the various areas and kills.
This could be a checklist for different areas you could get kills and just a simple showcase of "oh I never got a kill at the tent, lets try to get that to work" or various other types of kills that more inventive players would try for.