There are typically two types of gamers/developers: Ones who think Story is most important, and ones who think Gameplay in the same way. There are in betweens, as obviously, a game must have balance in order to be enjoyable in any way. However, designers everywhere love to do things to break this balance, in one way or another.
So, this is my personal list on the Seven Sins of Game Design.
1. Focus or rely too much on one type of gameplay.
2. Vary the gameplay too much.
3. Treat the player like they are an idiot.
4. Give the player far too much credit.
5. Be inconsistent.
6. Difficulty Spikes. The extreme variety.
7. When the Player Asks, “Why?!”
If you disagree with this list of sins, then that’s a good thing! It means that you’re a competent designer who has an opinion on how you think games should be made instead of just following what everybody else does. However, most people will agree with this list because it not just deals with the design of a game, but also the psychology of a game’s design. At it’s core, that is all game design really is: manipulation of the human mind. However, unlike games like Candy Crush Saga, FarmVille, and pretty much any game like those(even Team Fortress 2!), which manipulate the mind in devious and cruel ways that are inhumane to the point of affecting the mental condition of a player, a good designer of traditional video games will know that there is nothing wrong with a little manipulation if it’s purposes are helpful to the player, and make the player feel good in some way. That was the point of this article.