U.S. and U.K. markets saw sales increases, while Japan saw a decrease which is attributed to declining availability of software for Sony's Playstation 2 console, which is still very popular in Japan. The figures reveal that the U.K. has taken over as the second-largest gaming market, following the U.S., and taking Japan's former position.

Of the five most popular games across the three markets (U.S., U.K., and Japan), it should come as little surprise that three were Nintendo titles for the popular Wii console. The much-hyped Wii Fit came out on top in Japan, and was only slightly behind Mario Kart in the U.S. and U.K. markets.

What may be another indicator, however, of both game software sales as well as the Wii's consistent dominance of the console market, is the sales data for Call of Duty: World at War, the fifth most popular game on NPD's chart. The game, which allows players to re-enact many battles of World War II, was not released in Japan, arguably due to the content. In fact, many first-person shooter (FPS) games in Japan, as well as some other countries, like Germany, due to stricter ratings standards. The Xbox 360 is geared toward more mature gamers, and, possibly due to its close association with the Halo franchise, focuses more on FPS games than the casual gaming experience that makes the Wii appear more family-friendly. Is it possible that the Xbox 360 trails the Wii in international sales due to the focus?

However, games aimed at non-hardcore players aren't a guarantee of success, as Brighter Minds Media has discovered. The casual gaming company, which is behind popular games such as World of Goo, and Mystery Case Files: Return to Ravenhearst, .