Wait Wait Don't Tell Me:
Intuitively, most people fall under Tetris's spell upon first contact. The game design is impeccable and clearly uses the technology of its time perfectly. So simple is its gameplay that it seems as if you could simulate it perfectly in a physical prototype, but this is much more difficult with a little experimentation.
Without any context Tetris still makes sense. The pieces and lines don't represent wizards casting spells, giant robots doing battle, or dragons hoarding princesses/jewels. They simply are what they are. Extrinsic knowledge of the game is completely unecessary. It is a testament to Tetris's spectacular design that it stands solely upon it's design. It seems more than fair to say that no one is playing Tetris for the graphics or the story.
Also, the verbs of the game are kept to a minimum - move and rotate. That's all you can do. In fact, you can only move in 3 directions. A truly simple control set that is also immediately intuitive. Bang around on the controls for a few seconds and you'll know how to play the game.
Very limited move set: left, right, down, and rotate (cw/ccw). Easily translated to any input type.
Consider for a moment the seemingly endless possibilities within a game of Tetris and the complete lack of explanation of the rules of the game. As the saying goes,"Good art speaks for itself". Tetris is likely the best application of that sentiment as it pertains to game design.
With all the talk of "necessary" modern game components like narrative, graphic fidelity, and tutorials, Tetris stands like a statue on the geography of game design meant to remind us that truly great design can be legendary.
Airtight and Bulletproof:
Part of the reason Tetris is so successful is it's truly impenetrable design. It is based on squares, which are basically Points - this simplest, smallest part of the game world. Each playable Piece is made up of four of these Points. In fact, all possible combinations of four squares are represented:
All Tetris pieces - every 4 adjacent square combination excluding diagonals
What is your goal? Make at least one Line - the simplest possible 2D shape made with multiple points.
Completing a line in Tetris Zone for Mac
This is tremendously simple and intuitive. Design this simple speaks directly to our spatial reasoning and connects us to the gameplay instinctively.
The entirely of the gameplay space (the "Level", if you will) is on screen and your next piece is even revealed prior to being spat out for you to deal with. it is possible to completely enter a '"flow" state with Teris as you are capable of dealing with your very finite game world while planning for the next piece and simultaneously nursing a more strategic long term strategy.
Tetris on an 1986 IBM PC
It is difficult to conceive of a way to improve Tetris. Many will point to multiplayer version and spinoffs that include powerups. Most of these types of improvements offer more complexity which moves away from the "simplest possible solid game" ideal which, to me, Tetris represents in its fullest. Nothing external to your game and no need to learn that "blue is the freeze powerup". The pieces are simply pieces and they fill up the game space until you create lines or run out of space.
For my money "Torus" by Ben Joffe is the closest thing to a true improvement in this sense as is maps Tetris style gameplay to a 3D torus creating a wrap-around board. Really, you should play it. (Warning: It ads some no 4-square pieces)
Infinite Replayability and a PERFECT Intensity Curve:
A while back I wrote a blog here about the Time/Intensity Curve. This graph for Tetris is as close to perfect as it gets.
Graphing Time over Intensity - a basic metrics for game design
Yes, many other games have similar graphs where intensity parabolically increases over time, but Tetris is ruthlessly relentless in this regard. Pacman, Doom, Smite, Breakout, Bomberman... They all have great Time/Intensity curves, but Tetris gives you all the tools and knowledge you'll have the whole game at the very start and literally hammers you with increasingly faster gameplay until you die. Not only is the gameplay viscerally pummeling you, but also the game world visually fills with clutter.
There is no "Get Ready for Level 2" or end of level screen. Your only respite is death.
Likewise, the lack of narrative anchors the game to no mythology or franchise in a way that Bejeweled and Angry Birds would covet. In fact, I'd argue that the emergent narrative of the player's experience with the game over time, not just a single play session, is the narrative of the game. Many will work their way out of a tight spot of eliminate all squares on the screen and harken back to when they first accomplished that feat.
The lack of HD graphics makes Tetris timeless. Sure we can make it 3D and add particle effects and just "juice" it all we want, but it doesn't actually improve the design - although it may enhance the experience.
Alexey Pajitnov breathed life into Tetris at a time when personal computing and electronic game design was in its infancy. It is a perfect snapshot of that moment. In essence a time capsule.
1984: Ronald Reagan was POTUS, The 1st Macintosh, and Prince's "When Doves Cry" was #1
If you are interested in what people are doing with Tetris I'd recommend checking out my friend Martin's page - chesstris.com. He incorporates Tetris with stuff like Chess and Go to great effect. His non-Tetris-centric games are dope too.
Catch me on twitter: @devjana