The document discusses four classic games - tic tac toe, Pong, Snakes, and Bust-a-Move - that helped improve the gaming industry. It describes how tic tac toe is a paper-and-pencil game involving marking spaces in a 3x3 grid to get three in a row, Pong was one of the earliest video games involving simulated table tennis, Snakes was a popular 1970s video game made more famous when included on Nokia phones, and Bust-a-Move is a tile-matching puzzle game involving clearing bubbles without them reaching the bottom.