"To beat the game" means to successfully complete or master a particular activity or challenge. It implies that you have achieved success or overcome the obstacles presented within that specific game or task. Full definition
There's an achievement for beating the game in under eight minutes, so in theory it shouldn't take you too long, except you will die. (alphr.com)
It features online play, seven exclusive missions, and, after beating the game on normal difficulty, three exclusive gameplay modes are unlocked. (rpgfan.com)
I still can't beat the game on Normal, but it's been close at times. (gameological.com)