The Wii U has managed to move off of store shelves and into consumers living rooms. In fact, system sales have increased by more than 660 percent thanks to the release of Mario Kart 8. According to the International Business Times, 82 percent of those sales came from the Mario Kart 8 bundle.

Games make or break a system. Sure Blu-Ray functionality is nice, but you don't buy a console to watch "The Notebook" over and over again. You buy it to play games like Mario Kart 8. That being said, when you compare the Xbox One's Titanfall and the PS4's inFAMOUS: Second Son, two tentpole games, neither had the sales impact of the venerable Nintendo racer.

And while the once moribund system still hasn't caught up with the Xbox One and PS4 in terms of units sold, it can no longer be considered a laughingstock anymore.

But more good news surrounds the Wii U. Not only is Mario Kart 8 selling well, but it was also the second best selling game in the U.S. during the month of May, only behind record-setting new IP Watch Dogs.

"Wii U exclusive Mario Kart 8 races comfortably into second place [after Ubisoft's action adventure game Watch Dogs]," the company said. "The much-loved series makes an impressive debut, becoming the bestselling week one for any Wii U title since launch and the second-best in the Mario Kart series ever."

Things changed a bit last month. Japanese gaming website Gematsu provided June sales data (restricted to Japan) and Mario Kart 8 still was in the top 10 at No. 8. The Wii U system in Japan was the best selling non-portable console in Japan in June as well.

Yet, Nintendo isn't completely out of the woods yet. Since its November 2012 launch there've been few successful third-party titles released for the console. And most of those titles have been children's games. Nintendo needs to convince third-party developers (other than Ubisoft) to actively make and support mature, diverse games for the Wii U.

And then comes this sobering quote from Susumu Tanaka, Director and General Manager of Licensing Division for Nintendo, during the 74th Annual General Meeting of Shareholders Q&A session.

"With regard to Wii U, it is true that the number of titles is still limited and there is no huge hit from software developed by third-party publishers. For one reason, this is because the penetration of Wii U hardware has been slower than expected and this situation makes developers a bit wary of developing software for Wii U. We would like to continuously develop strong first-party software to drive hardware sales so that other developers feel confident to move into Wii U software development."

That being said, Watch Dogs hasn't yet been released for the Wii U console (you can pre-order it here). It's been delayed temporarily. But we may see this game reverse the lack of third-party hits.

Will you be buying a Wii U now that it seems to be having some U.S. and global success? Let us know in the comments section below.