lol, you’ll have to point me to particular bits of the soundtrack. What I looked up just now sounded very industrial, which isn’t always the closest thing to metal. (There are bands who straddle the two, including Strapping Young Lad, The Axis of Perdition, etc. The result tends to be very abrasive.)
What I’ve heard of Mick Gordon’s Doom soundtrack sounded very nu-metal and, yeah, djent. What I hear of Mick’s metal-flavored stuff in general usually seems to lean nu-metal. (On second thoughts, Aganos’s theme is really an exception to that. God, Aganos’s theme is great.)
Djent is something I can really take or leave (mostly leave), but there’s still a part of me that actively despises nu-metal. Not necessarily the music – it’s hasn’t been my thing for many years, and I think most nu-metal leans pretty shallow technically which is where they lose me, but each to their own, taste isn’t solely about technical chops, etc – more-so the marketing behemoth that formed around it. You had these bands spanning things like Linkin Park on the radio-friendly side, through Korn and Disturbed up to Slipknot on the edgier side, and it was always played as though metal as a genre consisted of the old greats like Sabbath and Iron Maiden and Pantera and Metallica and Slayer, and then kinda died after around about, say, the late '80s, and then someone like Korn brought it back in the mid '90s or so – this despite the latter really not really bearing much more than a superficial resemblance to the former. The craft is just really different: the former are really these instrument-driven technicians, they lean on very melodically complex riffs and leadwork and solos and a pretty vast and difficult playbook of distortion guitar and percussion techniques, and bluntly, neglect vocals as a serious instrument; the latter are very vocal-centric, their riffs are very monotone and simple and mostly rhythm-driven, their craft is more of a variety of pop or sometimes rap that exudes a metal aesthetic.
What really happened to the craft of those old bands is, it kinda went underground and forked in several directions: mostly American bands like Morbid Angel and Death and Suffocation took what Slayer was doing and made it into this lower-tuned, heavier and grindier thing that became death metal (this subgenre has mainly gotten more brutal and/or more technical as it’s matured and gotten more commercial, though some of it is tamer); bands like Carcass and Dark Tranquility married that emerging death metal sound with the harmonized, dual aeolian melodic leadwork from the likes of Iron Maiden to birth the Swedish melodic death metal scene (check out Arch Enemy and Amon Amarth for a sense of where this went); and bands like Bathory started playing this high-pitched fast-tempo tremolo-picking stuff that would go on to be codified in Norway as the notorious black metal genre by the likes of Mayhem and Immortal. (More listenable contemporaries include Keep of Kalessin and Watain.) This is the kind of stuff I meant when I said I struggled to think of an extreme metal soundtrack in gaming. You get tens of thousands of dedicated fans flying out to huge festivals around the world like Wacken Open Air each year to see this stuff (and plenty of those people are gamers) but it’s really hard to think of examples in gaming that draw on the craft of it in any meaningful way. I don’t really expect them to either, but it makes Gargos’s theme all that much more special and rewarding.
(EDIT: if you can’t see, most of the above band names are links, as are a few other things.)
Gargos’s theme straddles the blackened thrash area just off of Slayer, to my ear; Tusk’s theme sounds like it wants to be more like that Amon Amarth song linked above, but the techniques are lackluster, it lacks the deep, layered tremolo harmonies that makes Amon Amarth such a superior production. Whilst I don’t expect extreme metal in my video games, when I listen to a theme and think “that’s just a worse Amon Amarth song,” it’s kinda sad.
Anyway, I hope this answers a question that was…sort-of asked?