Kill 3 Rats
Avoid repetitive gameplay loops and create dynamic gameplay.
Credit for this one goes to YouTube Reviewer and Streamer Angry Joe Vargas. Repetitive gameplay kills fun and flow states. To keep players engaged, you have to design variety. This can be done in all kinds of ways from level design, to enemy variety to a well-designed difficulty curve. The main point is, there shouldn’t be any long slogs where nothing cool or interesting happens. Every 10 minutes of gameplay should be punctuated by something unique or interesting.