Firstly, Rodgers talks about the importance of the game's protagonist. The character's height, for instance, can make a big difference to how they are perceived. He says "Small/short = Plucky, Tall/Big = Heroic, Skinny = Fragile, Fat, = Funny" He then goes on to say that it's important to consider the characters reach, as well as creating metrics for your game world.
Rodgers explains controls and jumping, obviously an important aspect of platforming-based games. He really emphasises the importance of jump zones where the player jumps from) and landing zones (Where they can land safely). Also, he warns designers not to make the game feel inconsistent with the placement of platforms, in order to make the game fair.
In the document, there is a great deal about how to approach a falling character. For example, Rogers explains that most players will cautiously approach an edge and that the designer should think carefully to include a teeter animation to the game. On one hand, it acts as a warning, but it also disrupts the players’ control.
After talking about the basics, Rogers explain how to simply make the game more enjoyable though hidden items, design and aesthetics. For example, he says to make the music more exciting than what’s happening on screen and to create "Perceived Danger," where the character looks like they are in more danger than they actually are.
Finally, I will explain Rogers’ theories on enemies, which I found extremely useful. Although I am not sure that I will include enemies in my platform game (due to time restrictions) I still think it’s important to learn about them. He starts with explaining the basic kinds of enemies that are often experienced in these types of games.
He then stresses the importance that fighting enemies is supposed to be enjoyable, and that the designer must give the player reasons to fight the enemy. For instance, taunt animations are a good way to make the player dislike the opposition. Also, narrative elements can encourage the player to fight, such as the enemy kidnapping a girlfriend, burning down a village etc.
Overall, I gained a lot of knowledge from reading Scott Rogers' informal document and I think it has prepared me for designing my own levels.