Ah, Tetris. Chances are, if you're reading this on a computer, then you'll have at least heard of it, and probably have played it. Blocks fall down, you arrange them, and filled lines get removed. It is among the most popular games of all time, and definitely one of the most imitated. There are thousands of versions, with various extras and changes, for every platform imaginable. The quintessential version remains, however, the Nintendo version that defined the Gameboy's early years.
I'm not going to tell you how great Tetris is, or try and re-tell the story. Here, have some links if you want to know more: A History of Tetris, a story of Tetris told by one of its creators, an amusing tale of non-violent video games, for which the punch-line is Tetris, a compulsory Penny Arcade comic on the topic, an algorithmic proof of Tetris' difficulty.
Take it as given that Tetris, the concept, has some kind of universal attraction and approaches some kind of gaming nirvana of simplicity and infinite replayability. I would like to talk about Nintendo's implementation of Tetris, and why some of the minor choices it has made help make it great.
My interest in Tetris has been renewed because Pindy has been playing it on my antique original Gameboy. The contrast is almost completely washed out on the screen, the buttons creak, but the game still has all its addictive pull, and it is only because there's only one Gameboy that my thesis is now almost complete.
I wish I had time to make this a true comparative study, and to link to some versions of Tetris that take other options in their implementation. If you have examples to add, please submit them for everyone's edification. Note also that I'm not claiming Nintendo's version of Tetris to be the original or anything; just the best.
Now, to begin. Once there's falling blocks and arranging them, what else shapes Nintendo's implementation.
Blocks fall down the screen in smooth, single-pixel increments. Theoretically, blocks only need move in whole-block units and, indeed, this is the case in many implementations. Smooth drops give a better sense of speed and help with your timing, and are more pleasing to watch. As speeds increase, smooth drops matter less, but it's the principle of the thing.
On LCD-based implementations of Tetris, whole-unit drops are sometimes all that is possible. That's a fair excuse, but there is no reason not to do it for any pixel-based implementation.
Note that horizontal movements are still whole units; this makes alignment easier, which is important.
Blocks can be moved downward quickly, but not dropped immediately. By pushing or holding the down button, blocks are sped downwards; when the down button is released, the block returns to its original speed. This is a physically-curious phenomenon, but then so is the idea of slowly-falling blocks that can be manipulated in mid-air ("spooky action at a distance?" Not quite... although Quantum Tetris might be interesting).
The other option, taken by many PC implementations, is to have a "drop" button that instantly pushes the block straight down to where it stops. It's faster, but once the "drop" button is pushed there is no turning back, no chance to change your mind. Given that the horizontal placing of a block is determined by eye, usually against a plain background, it is more difficult to align a block from on high, so using the "drop" button increases the risk of error.
On slow levels, the "fast drop" option means that a block can be aligned approximately, dropped quickly to almost the ground level, and then adjusted if necessary. Sometimes it's necessary to tuck one block under another with a last-minute sidewards shuffle, for which the fast-drop is perfect. If there is only a "drop" option, there is no option but to wait for a slowly-falling block to arrive in the right place, then shift it. It's frustrating, a waste of time, and a hack.
Nintendo's implementation has two rotate buttons, clockwise and counterclockwise. This only makes any difference at all for the L-shaped tetraminos and the T-shaped one, and many implementations make do with only a single direction of rotation. This means that sometimes it will be necessary to make three rotations rather than one. With two buttons, the most rotation that is ever needed (for a vertical drop) is only two presses. If a mistake is made, if the correct rotation is overshot, it's much easier to correct it by using the other rotate button.
Having two rotation directions is also nice and symmetrical. Why should it be possible to rotate in one way, and not the other?
When a line is cleared, Tetris pauses momentarily before dropping the next piece. This serves multiple purposes. First, it allows the player to gloat for a second, and get confirmation of their own greatness in arranging blocks into a line. (That may sound dumb, but I'm being sincere - it feels good to get a Tetris, and you are rewarded with both sight and sound.) Second, it provides a pause for rest and recovery. Tetris is a game that can be played for a long time! Things get pretty frantic at about Level 12 or so, and there's been more than once instance where I have mopped my brow in the small pause provided by clearing a line.
The next block to fall can be seen ahead of time, allowing a limited amount of planning and anticipation. Tetris doesn't actually require there to be a Next Block option. It is such a good idea, though, that pretty much every implementation includes it, as had every block-puzzle-game ever since. Knowing the next block effects the placement of the current, plus lets you get your fingers ready for maneuvering the next block into position, sometimes at the warp-speed required at higher levels.
Clearing lines on faster levels earns more points. If you want to hit high scores, you're going to have to play fast. And, if you want to see the rocket (100,000 points) or the space shuttle (200,000 points), you're going to want to score as many points as possible on level 9 before the speed starts going up. Scaled scoring taunts you; it says, "what's wrong, can't you hack the speed? Then no point for you, you big baby!" This, and the ability to choose your starting speed, adds greatly to the replayability of the game.
All of these were choices that had to be made in the game; in hindsight, they all seem so obvious and so right, but they could have gone either way. It's debatable whether the success of the Nintendo version relied upon an excellent implementation, or whether it was just the Tetris concept, wedded to a portable handheld game console, that did the trick. Either way, I for one still love playing it, much more than any version I've seen since.
Posted by Casey at June 24, 2005 07:21 PMThe first version of tetris I played was called "Son of Tetris".
It included a feature that I liked, although I am sure the purists would be horrified. Every 20 or so pieces would be a "negative" piece. It would drop down, deleting everything in its path until some internal counter of the deleted blocks reached zero and it would solidify in place. It was nice to know that, no matter what mess you had made, the next block might be the one to wipe it clean.
I once saw a game with a trick "boss button"! When pressed, it brought up the Tetris title screen! It had some subtitle saying something like "What were you expecting? Lotus 123?"
Someone I knew once commented that the reason women liked Tetris was because they liked to tidy things up and make them neat!
I went through a huge Tetris phase on my GameBoy. I used to dream about Tetris in my sleep and play those S-shaped pieces with ease. No I wasn't a geek at all.
Posted by: AugustusGloop at June 28, 2005 05:45 PM