Gamasutra is running a feature about how the ease of learning new games depends on the types of games a player has seen before. "Pong offers quick pick-up not because it is easier to learn than Computer Space (although that was also true), but because it draws on familiar conventions from that sport. Or better, Pong is 'easy to learn' precisely because it assumes the basic rules and function of a familiar cultural practice." The article goes on to examine how the need to master some games is more akin to the "catchiness" of a song than an addiction. "Familiarity relates to another of Barsom's observations: repetition. Catchy songs often have a 'hook,' a musical phrase where the majority of the catchy payload resides. Indeed, the itch usually lasts only a few bars, sometimes annoyingly so. But games rely on small atoms of interaction even more so than do songs. The catchy part of a game repeats more innately than does a song's chorus. In Tetris it's the fitting together of tetrominoes."