"To expand the gameplay" means to enhance or increase the available options, features, or experiences in a video game, making it more varied, interesting, and engaging. Full definition
It's a neat way to expand the gameplay possibilities the worlds bring, and really changes the basic structure of the title and how it works. (gamingreinvented.com)
We kept this feature and started thinking about expanding the gameplay mechanics to make the game more challenging. (gamesauce.biz)
Future installments get a great launch pad with potential for expanded gameplay. (geardiary.com)