Call of Duty is the U.S.' best-selling (retail) game for 2015

The NPD group, which specializes in retail sales tracking, has released its chart of the best-selling physical copies of games in the U.S. for 2015. Call of Duty continues to lead the pack.

The firm says that new video games generated $13.1 billion in retail sales for 2015, VentureBeat reports. 

The top-selling list isn't going to surprise you very much, but here it is. Note that while the NPD does not offer sales numbers, the platforms listings that follow game titles are ranked in order of best-to-worst sales-wise. This means that Black Ops III sold best on Xbox One, for example. Digital download numbers, we must stress, are not included in this ranking. 

Games sold as pack-ins with console bundles also don't count toward the list. 

Call of Duty dominated, with two games on the list, but rumors of slowing sales dog the series. Analyst Ben Schachter pointed out that Black Ops III took three days to make the numbers its predecessor made in just one. 

For a real contrast, check out our report on the top 10 best-selling games for 2015 in Japan, as compiled by Famitsu; it's dominated by Nintendo 3DS titles. There isn't a single one on this list.