Another category that is hard to explain in general, but easy to recognize in practice. Don’t think about expanding the tutorial with bad jokes. Think about how the character sprites move and react in a game of Metal Slug at the arcade. Or how your character in many games does a take to the camera when you’re idle. Perhaps the items and enemies are named in funny or cute unexpected ways. Maybe the elites and bosses have a rare unexpected non-player focused behavior. Maybe part of the background reacts when you thought it was static. Many good arcade games and great survivors-likes have their own unique subtle humor.