Lara Croft had a big December.

Microsoft has confirmed that the adventurer’s latest outing, the excellent Rise of the Tomb Raider (one of the 10 best games of the year), has reached “well over” 1 million copies sold through to consumers. In a tweet, Xbox marketing exec Aaron Greenberg specifically noted that Rise madeĀ a lot of those sales in December. And that would make sense, considering the game didn’t chart on the top-10 list of best-selling new games at U.S. retailers last month, according to industry-tracking firm The NPD Group.

This also puts a bit more of a positive shine on the Xbox One’s holiday lineup since Rise of the Tomb Raider was one of the system’s big exclusives during the holiday season.

This news also suggests that Rise of the Tomb Raider could have strong legs. The action-adventure game, which tells a coming-of-age story for the rebooted Lara Croft, debuted on the Xbox One the same day that Fallout 4 released for PlayStation 4, Xbox One, and PC. Publisher Bethesda’s massive post-apocalyptic role-playing game turned into an instant success and was one of the most talked-about releases of the year. Rise of the Tomb Raider seemed to wither under that shadow. But since then, with Rise getting high praise from critics and landing on numerous “best of” lists for 2015, the game has emerged as something of a sleeper hit.

Rise of the Tomb Raider will debut on PC this month, according to Microsoft. That release could now benefit from some space from the crowded fourth quarter, along with all the positive word-of-mouth buzz.