Pokémon X/Y
The mainstream Pokémon series games spent over two decades as 2D, top-down RPGs in a fairly conventional 8-bit/16-bit manner; it wasn't until the release of Pokémon X and Y in 2013 that they eventually became more current in style, employing fully 3D polygonal visuals for the first time. Not only were they technologically innovative, but other elements firmly rooted in the games in the past as well, including trainer customization and touchscreen interaction with Pokémon.
Unsurprisingly, the long-awaited Pokémon X and Y were tremendous critical and economic triumphs (albeit, strangely, the two versions rank somewhat differently in Metacritic's rankings for no apparent reason!). The series has progressed significantly since then, but this is the first new-generation game for the 3DS, and it adds significantly. Play it for the historical significance as well as the opportunity to capture 'em all.
Link to buy: amzn.to/3MJz4Rp