"To polish the game" means to make improvements and add finishing touches to a video game to enhance its quality and make it more enjoyable for players. Full definition
I'm about a quarter of the way through, and so far, it's just a more polished game with less punishing gameplay. (gameological.com)
I've had the opportunity to play some of the most well polished games ever made, and there are still plenty of titles out there for me to snag. (n4g.com)
It is a very polished game with exceptional detail on every wall, corner, building, character and environmental element in a destructive yet magical land. (thisisxbox.com)