Nintendo Co. is gambling that it can sell millions of Switch consoles this holiday season by introducing a new "Pokemon" game that interacts with the free-to-play mobile hit "Pokemon Go," as well as a new character that resembles a hex nut.

"Let's Go Pikachu" and "Let's Go Eevee," which went on sale worldwide Friday, are the first titles from the popular series for Nintendo's newest console. Armed with richer graphics, the games are designed to appeal to the 850 million fans who have played "Pokemon Go." Those who buy the new games can sync their smartphones and Switch consoles through a Bluetooth connection and doing so lets users transfer pocket monsters between the mobile app and Switch games, and also unlock Meltan, the new character.

Nintendo is aiming to boost Switch sales during an otherwise lackluster year for software releases. Analysts point to 2016 when the debut of "Pokemon Go" reignited interest in buying 3DS consoles to play more games in the series. They estimate Meltan can help sell 7.5 million units of the new titles by March, according to four analyst projections compiled by Bloomberg. "Meltan" was trending on social media among Pokemon fans within hours of the game's release.