Let's Play: Doom Eternal Part 4 - My Castle of Grayskull 

9:19 Here's where the platforming gets fun. I'm one of those that hated it but you are a lot better at it then me. Those little flying bird-things and imps got on my nerves so bad in this game. 41:04 Believe me as difficult as that island fight was-the game gets a lot harder! On the cacodemons use the grenade launcher on your shotgun. That's about the quickest way to kill them, as they are literally bullet sponges until you get the super shotgun.

The auto shotgun is a uctually pretty useless in this game it is powerful but slows you down quite a bit firing sticky bombs is much more effective and faster.