In the Mario series, which game introduced Mario's Backflip ability?

The answer is actually incorrect. The game that introduced Mario's backflip ability was Super Mario 64, released for the Nintendo 64 console. In this iconic 3D platformer, players could perform a backflip by pressing the jump button while standing still and then quickly tilting the joystick backward. This move allowed Mario to reach high platforms and perform impressive acrobatic maneuvers, making it a memorable and important addition to his repertoire of abilities in the Mario series.