It's usual in black metal to encounter repetitious passages, which isn't bad in and of itself, but it could easily get boring if there's nothing that snaps its fingers to engage you. I think these guys are effectively managing the situation with percussive elements--so you can dig deep and ride this thing straight down into the Dark Underbelly.
Also: HGD, is that a Didgeridoo? <3
Favorite track: The One Who Waits on the Other Side.