There are a total of 21 Chapters in the main story, So will need to run a second Playthrough you'll have this trophy , If you do not not want to do a full playthrough again the Quickest Chapters to beat would be
Episode 3 - Chatper 1 and Episode 3 - Chapter 2.
On Episode 3 - Chapter 1 you have to defend the train which can take 10 - 15 mins depending on difficulty.
On Episode 3 - Chapter 2 you have to kill some attacking enemies and then two boss Akrid.
Honestly I prefer Episode 3 - Chapter 2 its less boring and you can work on the damage Nom's and Killing 30 Bosses.