The alpha release of Dusk's SDK brought mod support to the retro shooter and, as we noted at the time, that included the ability to play Quake and Half-Life maps in Dusk. The latest update adds custom music and that is why you can, as New Blood Interactive demonstrate in the video above, play Half-Life maps with Doom's music in Dusk.
That's Anomalous Materials up there, the second level of Half-Life, with Dusk's scientist enemies—who were inspired by Half-Life's scientists, bringing them full circle.
Though it's early days (Steam Workshop support is planned in the future), Dusk's modding scene has already brought us an equivalent of the classic NUTS.WAD, a joke mod for Doom with 10,617 enemies that was unplayable on PCs at the time, and a giant anime sword from the Fate/ series.
The full patch notes are actually pretty long.