Pokémon Black and White mark a soft reboot of the Pokémon franchise. Set in the far-off region of Unova, players embark on a brand new Pokémon journey, but must contend with the sinister plans of Team Plasma, and the mysterious stranger known as N. Players will meet an entirely new cast of Pokémon, a first for the series, along with all-new battle modes, triple and rotation battles! Featuring one of the most detailed plots of any Pokémon game, a season mechanic, and new minigames such as Pokémon Musical, Black and White is an adventure to remember in the Pokémon franchise.
From the game's Wikipedia page:
"Pokémon Black Version and Pokémon White Version are role-playing video games developed by Game Freak, published by The Pokémon Company and Nintendo for the Nintendo DS. They are the first installments in the fifth generation of the Pokémon video game series. First released in Japan on September 18, 2010, they were later released in Europe on March 4, 2011, in North America on March 6, 2011, and Australia on March 10, 2011.
Similar to previous installments of the series, the two games follow the journey of a young Pokémon trainer through the region of Unova, as they train Pokémon used to compete against other trainers, while thwarting the schemes of the criminal organization Team Plasma. Black and White introduced 156 new Pokémon to the franchise, 5 more than the previous record holder Pokémon Red and Blue, as well as many new features, including a seasonal cycle, rotation battles, fully animated Pokémon sprites and triple battles. Both titles are independent of each other, but feature largely the same plot, and while both can be played separately, trading Pokémon between both of the games is necessary in order to complete the games' Pokédex.
Upon their release, Black and White received positive reviews; critics praised the advancements in gameplay, as well as several of the new Pokémon introduced. Reviewers, however, were divided on some of the character designs, and some critics felt that the games did not innovate as much as expected. Nevertheless, the games were commercial successes; prior to the games' Japanese release, Black and White sold one million consumer pre-orders and became the fastest Nintendo DS titles to sell five million copies. As of September 2017, the games' combined sales have reached 15.64 million, putting them amongst the best-selling games for the Nintendo DS, but still being outsold by their predecessors, Pokémon Diamond and Pearl. Sequels to Pokémon Black and White, Pokémon Black 2 and Pokémon White 2, were released in Japan for the Nintendo DS in June 2012, with October releases in North America, Europe, and Australia."