[Gamasutra analyst Matt Matthews examines NPD results for U.S. video game retail in January, including close-up looks at rising Kinect popularity and "extended declines" in Wii and DS hardware and software sales.]

According to the latest NPD Group sales estimates, U.S. retail video game sales are still contracting. On Thursday the firm revealed a 4% decline in overall sales, with both the hardware and software segments contributing to the shortfall.

Only the accessory segment showed a year-over-year increase in revenue, with Microsoft's Kinect and Sony's Move likely contributing most of that growth.

Below these figures are some intriguing trends, including the continued rise of Microsoft's new motion control system and growth in Sony's software revenue.

We also look at Nintendo's plight as both the Wii and DS experience extended declines in hardware and software sales.

Along the way we also find the opportunity to comment on Dance Central sales as they pass a new milestone and put the launch of LittleBigPlanet 2 in historical context.

January At a Glance

With only one month in the year so far, our monthly review of the top-line figures is somewhat simpler than usual. As the chart below shows, both software and hardware revenue were down approximately $30 million each.

The accessories segment showed a $12 million, or 5.5%, gain. Along with Sony and Microsoft's new motion control systems, it is likely that points/money cards for Xbox Live and PlayStation Network continue to contribute to the growth in this segment.

According to industry analyst Michael Pachter of Wedbush Securities, overall software unit sales were down just 1%, with most of the software revenue decline coming from the 4% decline in average software prices.

For the record, the NPD Group is now clearly labeling their media releases to indicate that the figures include only retail sales. They are providing quarterly estimates of extra-retail sales, including mobile games, downloadable content, and casual games, along with other segments, but those figures are not included in the figures above nor are they considered directly in this analysis.