How does physics help in developing computer games?
Without knowing anything about Newton's laws, gravity, conservation of momentum, or fluid dynamics, even small children have a pretty good sense of how objects move in the real world. You learn to predict the influence of gravity on the motion of a thrown object the first time you play with a ball. You come to expect that sort of behavior in physical objects.
Computer games need to recreate similar motions on the screen to make a game seem realistic and to help the player use the knowledge they already have about the real world in the game. Games can play around with those laws and experiment with different sorts of gravity. But if the simulated world of the computer game is very different from the real world, players may need some time to learn to navigate the strange physics of this new reality.