The game of Snake

Snake is all about accepting a self-imposed challenge. Once a tiny snake starts going, nothing in the game forces the player to direct it to pick up fruits, and thus grow, and thus become more and more difficult to handle to pick up more fruit. There is no game taking control away from the player in order to get fruits or any timed losing condition as in Alien Invaders / Tetris / Arcanoid where constantly moving rows of invaders, or tetraminos, or bouncy ball cause "Game Over" if one touches your ship or cross a certain line of the screen. Going in pointless circles (or remaining motionless) in such games is not an option while, theoretically at least, the snake can go in small pointless circles in hours without ever growing if the player wishes it to be so – the only growth might happen from unintentionally nabbing a fruit when game randomly spawns it too close, and with slight attention to the screen even this can be avoided.

But because 1) going in circles is boring to the player and 2) the only counter in game is a number of fruits the snake eats, not the time it exists, the default sense of progress would only be obvious from getting more fruit, thus making the game more and more difficult until snake reaches the ultimate length and fills the screen with only its own self. 

Snake is becoming the totality of its universe; from youtube video

Remarkable thing in Snake is how clearly the difficulty scales. Within the game itself there is no difficulty slider, and neither the game secretly adjusts things the screen after X many victories or failures; there are no helpful pickups giving special powers. Get one fruit = grow one square longer = have one less space to maneuver with. Each scored point immediately moves difficulty a single step up from 2 to [however big the box X times Y resolution is], with gameplay gradually changing with each new fruit from free-roaming within the box and avoiding its edges to almost a rhythm game of turns and twists which have to be timed just right in order not to intersect snake's own body. One interesting thing is how with growing length snake's body also inherits more and more of the history of its own movement through the world, as its shape becomes more and more defined by where it picked up the earlier fruits. From a certain perspective, latter-game snake navigates the world of its own past successes which now became hurdles; abstractly it might be defined as navigating the world of its own memory and having limited opportunities to make a new one.

As the snake's body grows player also has less and less choice from which direction to approach the new fruit, thus making the skill of ever-vanishing free space more and more important. As the game progresses the space where the fruit might spawn becomes more and more confined – to a single line in later game, right on snake's path, thus making the growth unavoidable; from a certain length there is no longer an option to stall and endlessly go in circles, only to keep growing bigger or fail.

It can be said that snake's world keeps on moving but the space to experience it, to make new twists and turns, becomes less and less – a sort of liquid petrification state until the last fruit is eaten, and the game, and snake's existence both end. 

The snake is like Ouroboros, but, unlike Ouroboros it dies when it finally encircles the world;
from Clipart Library

Yet, it is completely up to the player's skill how to deal with those increasingly difficult circumstances, how to keep navigating the world. There are no impeding debuffs or helping tools to give a temporary respite, and the difficulty keeps consistently ramping up unless intentionally stalled. Players who achieve high results seem to have good reflexes but also a kind of strategy on how to maneuver snake – while there is still space – so its growth and unwieldiness doesn't hinder them too much later, up ignoring some fruits in order to create a better 'body history' trail for future. 

The game ultimately ends where the world of snake becomes the snake, but in no way this ultimate victory is a special moment. (at least in classic old Snake) There is no winning screen, no bursts of fireworks – simply a score, different from any other score by only a bigger number. With current technology there can be external motivation in showing off the ultimate success as a recording and there are probably game variations with leaderboards and such, but when the game was first made, all motivation to win must have been player's own, to see how far they can go. Another interesting thing is that ultimate high score has very little variety: as the snake has limited area to fill, the difference in high score can only be made in earlier stages of the game, but because snake grows so fast, the necessity to navigate its own 'body history' comes rather sooner, and the high score won't be so drastically different as in, say, 'Tetris' or 'Pac-man' where new stages will come as long as player'll keep on managing them. Snake sort of sets the ceiling to its own difficulty, and the victory of the game is simply reaching this ceiling. 

What I am finding interesting that this kind of dynamic (with constantly ramping difficulty directly tied to player's skill in succeeding) is not repeated, to my knowledge, beyond similar Snake-like games. 'God Hand' and a few other games have adaptive difficulty, but this isn't the same, as in those games the difficulty goes up and down with victory and defeat, while in Snake difficulty at best can be stalled but never regressed. It would be interesting to see a more complex game with this kind of design principles.