Nintendo on Tuesday announced that it sold more than four million of its sophisticated 3DS handheld videogame gadgets in the United States by end of 2011. Consumers also snapped up versions of beloved \"Mario\" franchise videogames tailored for the handsets, which feature 3-D graphics without need of special glasses. The Japanese videogame titan said that it sold more than a million copies each of \"Super Mario 3D Land\" and \"Mario Kart 7\" in the United States for play on 3DS devices. \"One of the strongest software lineups in our history helped Nintendo have a great holiday season and to close 2011 with a full head of steam,\" said Nintendo of America executive vice president of sales and marketing Scott Moffitt. \"The prospects for 2012 are extremely promising,\" he added. Nintendo cut the price of 3DS devices by $80 to $170 shortly after its release last year, due to sluggish sales. Trends toward enjoying mobile games on smartphones or tablet computers have made it tougher to sell handheld devices designed exclusively for videogame play. US sales of Nintendo\'s Wii videogame consoles hit 4.5 million units in 2011 despite the promise of an enhanced successor, the Wii U, on the horizon. Wii U consoles, which enhance motion-sensing wand play with tablet controllers, are to be shown off at an Electronic Entertainment Expo extravaganza in Los Angeles in June. By the end of 2011, \"The Legend of Zelda: Skyward Sword\" became the 45th Wii title to sell more than a million copies in the United States, according to Nintendo.