Mario, the world’s most famous plumber, debuted in a new go-kart game this spring but failed to meaningfully lift Nintendo’s bottom line.

Though Nintendo has sold nearly three million units of the “Mario Kart 8” game for the struggling Wii U console, the Japanese game maker failed to generate significant momentum for the system and reported a fiscal quarterly loss for the period ended June 30.

The company’s Wii U system is the successor to the popular Wii, though it hasn’t sold as well as Nintendo had initially expected. Through June 30th of this year, Wii U has sold 6.68 million hardware units and nearly 37 million games–still under the gaming company’s initial targets (which were later trimmed as sales disappointed).

Nintendo is facing pressure as its gaming consoles, often popular with younger children, are competing with mobile devices that have thousands of gaming apps. Kids and their parents are spending more time playing with apps on iPads and other mobile devices, taking away attention from the Wii platform and other traditional hardware consoles. Nintendo has sought to bolster its software offerings for the system and in the latest period, the company said “Mario Kart 8” helped build interest for the overall Wii U system. On a positive note, Nintendo still believes it can sell 3.6 million units of the hardware this fiscal year.

For the three months ended June 30, Nintendo reported it sold just 510,000 Wii U consoles and about 4.4 million games, with the software side of the business bolstered by the May launch of “Mario Kart 8,” which sold well. Nintendo 3DS hardware sales totaled 820,000, with 8.6 million of that console’s games sold in the latest period.

Overall, Nintendo reported it swung to a net loss of 9.9 billion yen ($97 million) from a profit of 8.6 billion a year ago. Total net sales slipped 8.4%.