Building a simple level.

Level building blocks:

• Concept
• Enviroment to exist in
• Beggining 
• Ending 
• Goal
• Challenge to overcome between the character and goal
• Reward 
• Way of handling failure

These are what are generally required to build a level. There are other elements but these are crucial. Without them the level will feel incomplete. Story is not one of these elements be although story can enhance a game it is far from needed.

Key lessons:
Dissonance is when a part of the game may seem out of place or goofy to a player.
The best gameplay mechanics are those that don't require explanation making the player feel clever and keeping the designer behind the scenes.
'Game logic' s where a player can assume that certain situations or objects would behave more predictabley than in real life.
The less the player can blame the designer for failure the better. Being able to blame the designer reduces incentive for the player to continue playing the game.
The more the player can complete the level through simply interacting with the game the better.
Completing a level can be a reward in itself.