Something I find interesting is how it compares to another famous score from a retro(?) FPS, Doom and Doom Eternal. Don't get me wrong, Mick Gordon's music is fantastic, and I, as a metalhead who likes djent, count it as the most hype music ever made. But almost all of it is about the combat and the Doomslayer himself.
Ultrakill OST, on the other hand, is about the places V1 intrudes and the characters it faces. Not only it allows the music to be so varied, but it also adds to (or even subverts) the impression these places and characters make.
The difference between Divine Intervention and The Death of the God's Will expresses the change in Gabriel's attitude just as much as, if not more than, his own words, despite being more or less variations of the same track. It is an angelic hymn versus a power metal track. It is greatness versus blind rage.
The difference between Order and War is the difference between the kind and noble judge and the madman.
With this contextual relevance, the music of Ultrakill has more in common with the Bloodborne OST than Doom. And in some cases, it even sounds more like the scores from Bloodborne.