Can Mario and Luigi level up Wii U sales? Source: Nintendo.

Despite strong sales of Mario Kart 8 for the Wii U, shares of Nintendo (NASDAQOTH:NTDOY) have underperformed over the past week. Is that fair? What's the key to reversing the trend?

Guest host Alison Southwick puts these questions to analysts Nathan Alderman and Tim Beyers in this week's episode of 1-Up On Wall Street, The Motley Fool's web show in which we talk about the big-money names behind your favorite movies, toys, video games, comics, and more.

All told, Mario Kart 8 sold an estimated 1.2 million copies in its debut weekend, one of the fastest starts in Wii U history. Yet the console needs the boost having sold just 6.2 million units since its November 2012 debut. For perspective, consider that gamers have purchased 4.5 million Xbox One units and 7.7 million PlayStation 4 units since those consoles arrived eight months ago. Nathan says that if Mario Kart 8 can boost the Wii U's totals, it'll be a win.

Tim agrees, saying that Nintendo's fortunes hinge on improved console sales. Whereas Microsoft (NASDAQ: MSFT) has made a habit of selling the Xbox at a razor-thin margin, Nintendo has a history of selling highly profitable systems. The Wii U is an uncommon blemish in that regard.

The good news? In Nintendo's home market of Japan, Wii U sales recently outpaced PS4 sales by about 3-to-1. Mario Kart 8 seems to be contributing the gains, which is unsurprising when you consider that retailers have sold more than 35 million copies of Mario Kart for the original Wii console. Still, Nathan and Tim say it's just the sort of win Nintendo investors need right now.

Now it's your turn to weigh in using the comments box below. Do you see Nintendo stock outperforming from here? Click the video to watch as Alison puts Nathan and Tim on the spot, and then be sure to follow us on Twitter for more segments and regular geek news updates!