I am deathly afraid of game design. When I have an idea that is super cool and proves to be exceptional, I get anxious even adding things to it (even though there are things that need fixed!). I think this is healthy (lol), it creates the balance of "I don't want to add things that will ruin the design" and "I need to rework this because it just isn't right". I have gotten better at noticing the terrible tangent, the incredible urge to keep adding things and end up getting far away from the original design and direction. I think sometimes though, I get so afraid of adding things that I actually miss out on cool aspects of the game that could be better!
Do you struggle with this? What ways do you curb the sensation of adding "just one more thing"? How do you know when adding something is needed?