"Gameplay modes" refer to different ways or styles of playing a video game. It means there are different options or settings within the game that change how you play and experience it. Full definition
«Destiny 2» will be getting a new gameplay mode in fall that developers are set to debut next month. (techtimes.com)
It offers multiple type of gameplay modes including a battle mode. (gearnuke.com)
Apart from that, the game also offers a variety of different gameplay modes to allow for some great longevity, not to mention some great multiplayer fun. (impulsegamer.com)