Ahead of its time and quite experimental for a video game soundtrack in 2004.
It's a very impressive mix of unsettling grime and cold surrealism - mixing elements of industrial, dark ambience, as well as some trip hop. But this avant-garde approach perfectly suits the dreamlike narrative and darker tone of the game, as it emulates Agent 47's wounded state and his grim fever dreams.
What makes this soundtrack even more impressive is how electronic it is. Many video game scores of the time were comprised of orchestral pieces or rock anthems. But Contracts pushed the boundaries of what video game scores could be, with heavily electronic compositions and effects that could immerse the player into the dark psyche of the protagonist and the unpleasant underworld.
No wonder this soundtrack won a BAFTA.