In the movies, Vin Diesel's Riddick character is unrelenting and remorseless. He's awesome. Blessed with supernatural night vision, he moves quietly through the dark, brutally eliminating anyone that stands between him and surviving whatever unlucky situation befalls him. 2004's excellent Escape from Butcher Bay accurately translated this feeling of, for lack of a more eloquent term, being a complete badass from film to a first-person action-adventure game that had just the right blend of sneaking and shooting.
Butcher Bay turned out to be an unexpected hit, standing out in a year stocked with some of the last generation's greatest games. It was mysteriously passed over for inclusion in the Xbox 360's backwards compatibility program, so its remastering and overdue release in the Assault on Dark Athena package is cause for celebration. Since there are plenty of Butcher Bay reviews already out there, there's no need to dwell on the old content other than saying it still plays great, and now it looks great.
It also has the unfortunate side effect of highlighting the shortcomings of the new content. The continuation of events immediately proceeding Riddick's escape from the Butcher Bay prison, while definitely substantial enough to warrant a stand-alone product, deviate too far from what made the Butcher Bay game so great and the Riddick universe as a whole so enjoyable.