The stroller "speed"run category is the pacifist run turned up another degree of difficulty-- you're not allowed to run or use strafes. Vytaan records his attempts to work through ep 1 under these conditions.
That Nukem Guy amped up Knee Deep in the Dead (minus the secret level) by adding assets from Doom 2. It's nothing crazy but the difficulty really ramps up when you're expecting a few imps and cacodemons and you're met instead with revenants and pain elementals. Fortunately the SSG makes an appearance to level the playing field.