I was just discussing the idea with a colleague of mine during lunch that many gameplay mechanics and elements were standardized in ways that were arbitrarily made.
One extremely common one is the progression of 2D games that happens from left to right. As examples you have Super Mario, Sonic, Golden Axe, Streets of Rage and an endless number of platform games. I was left wondering how this came to be. An idea was that this was an artifact from the way we read, also left to right, but that idea suffered from other cultures/languages having a different progress when read. As an example of this we have Japanese, where the writing is done right to left.
Another progression that happens is bottom up in games. The player/situation starts at the bottom and progresses up. Examples of this are Tetris, Space Invaders and scroll-down shooters by definition among others. This may have a number of explanations such as concepts of gravity (Tetris), situation (Space Invaders) but in case of scroll-down shooters, apart from the name of the genre, doesn't seem to have any special reason why this happens. Perspective might explain some, but it feels copping out to use this as a reason.
So, any interesting ideas or explanations about why progression in 2D games happens mostly in a left to right, bottom up manner?