Yeah, Eternal is very "ADHD kill spree" mode. Still good fun once you get over the UX though as the level progression is very well done. It gets pretty intense later on.

Try Doom 2016 if you haven't already. You can turn off some of the arcardy elements in the "advanced" video settings.

Turning off that, crosshairs, certain HUD elements, adding film grain etc. makes it more cinematic...