Wii Sports offers a similar lesson. The broad success of the Wii console comes in no small part from the effectiveness of this launch title. Wii Sports is really just Pong warmed over, offering simple abstractions of well-known sports that are themselves quite complex to learn, but which large populations have managed to understand over time.
What about so-called casual games? Tetris isn't really easy to learn either. Sure, it offers simple controls and a comprehensible goal, but nothing about those controls or that goal is obvious or intuitive; they are not inherently familiar ideas.
But the tetrominoes, those are familiar. Tile games find their roots in dominoes, an ancient game, one millennia old in its earliest forms.
Polyominoes (a shape made of a certain number of connected squares; Tetris pieces use four) have been common elements of puzzles since the early 20th century, most frequently found in tiling puzzles (like pentominoes) or assembly puzzles (like tangrams).
Tetris cleverly combines both the assembly and the tiling varieties of polyomino puzzles, asking the player to construct a small sub-tiled region (a line) by making micro-assemblies of two or three blocks.
As all of these examples suggest, familiarity builds on prior conventions. Pong builds upon table tennis, which builds upon tennis, which builds upon racquets. Tetris builds upon pentominoes, which builds upon dominoes, which builds upon early games of dice and bones.
Games can also produce their own conventions, which become familiar enough to be adopted later in the same way that Pong adopts table tennis. The falling tetrominoes of Tetris, for example, inspire the falling blocks of Columns or Dr. Mario or Klax -- games that make modifications to familiar conventions from earlier games as they congeal.
Likewise, the familiarity of subjects helps apologize for unfamiliarity of form. George Parker's early game Banking (1883) built upon players' basic knowledge of financial practices. Popular casual games in the vein of Diner Dash do the same, relying on player's familiarity with waitressing, hairdressing, or other professions.
No matter the case, the result is important: the maxim "easy to learn" is misunderstood. Mechanical simplicity is less important than conceptual familiarity.
So much for "easy to use." What about "hard to master?"
Some games are profound enough to deserve the provocation toward mastery, but not many. Chess and Go do by virtue of complexity and emergence: they are games that offer such rich and intricate variation that only careful, long-term study can produce proficiency.
This is why the concept of a "chess master" means something more than simply someone who just plays a lot. Chess and Go are games for which mastery is definitively "hard."
In her GDC 2009 microtalk, Tracy Fullerton observed that the very hard mastery of such games inspires less able players by tracing the edges of the game's beauty. We might call this the terrain of sublime mastery. And there is indeed a fearful wonder in this territory. But it is also a weird mastery, one that sits at the fringes of a game, alienating as much as it inspires.
The standard rationale for mastery makes appeals to the depth of a game, suggesting that the value of its design cannot be expended in only a few sessions, but would require innumerable replays, perhaps theoretically infinite ones, to reveal all its secrets. The problem is, sublime mastery is usually desirable only as an ideal, not as an experience.
It's no secret that Nolan Bushnell was a fan of Go. Atari, after all, is a technical term from that game.
So it is easy to assume that the "difficult to master" portion of Bushnell's Law refers to NP-hard problems of the Go variety. But the second portion of his proverb suggests a different meaning.
That a game should "reward the first quarter as well as the hundredth" (this was the era of the coin-op) suggests nothing about the cosmic intricacy of a game like Go.
Instead, it suggests that a game ought to produce allure many times. Bushnell's Law makes no claim about the kind of appeal a game ought to make on the tenth or hundredth playing, nor if that allure ought to be entirely different or new every time.