Need help with essay. (Comparing and contrasting movie; Blade runner & Shaun of the dead

Hey guys I have to write an essay comparing and contrasting movie themes for a class I'm taking. The two movies I have to write about are Blade Runner and Shaun of the dead. The theme I'm choosing between the two movies is (Apocalypse).

One topic of the essay I have down is how fear of generations have changed.
For example, a lot of cyborg movies were coming out in the 80's and currently a lot of zombie movies are being released and seems to be an actual fear as i assume it was with cyborg back in the 80's.
After comparing the different generations fear I get stuck.
Im not sure what other topics or what to compare to now.
So if y'all could help me with ideas that'd be awesome!