Nintendo Co. can finally claim a megahit smartphone game with its new Mario Kart Tour, which has been downloaded 123.9 million times in its first month and comfortably eclipsed the company's previous mobile game debuts, according to data from app research firm Sensor Tower.

"The racing app is Nintendo's most successful mobile game launch by downloads so far, eclipsing Super Mario Run's 21.8 million downloads more than five times over," Katie Williams, mobile analyst at Sensor Tower, wrote in a blog post.

The game raked in revenue of $37.4 million in its first month, second only to Fire Emblem Heroes' $67.6 million, according to the researchers' data.