Nintendos handheld business is booming right now, and the company has the stats to prove it. In its annual overview released today, the company says it sold a record-breaking 16 million 3DS games in 2013, which translates to a 45 percent increase over last year. US consumers played a big part in Nintendos bumper year, accounting for 11.5 million of Nintendos 35 million 2DS and 3DS lifetime sales.