Designing arcade games for modular expansion requires careful planning to ensure scalability, flexibility, and long-term player engagement. Here are the key considerations:

1. Scalable Architecture: The game’s core architecture should support easy integration of new modules, such as levels, characters, or mechanics, without disrupting existing gameplay.

2. Standardized Interfaces: Use standardized APIs or frameworks to ensure seamless compatibility between modules, reducing development time and technical debt.

3. Player Progression: Design modular content to align with player progression, ensuring new additions feel natural and rewarding rather than disjointed.

4. Performance Optimization: Modular expansion should not compromise performance. Optimize asset loading and memory management to handle additional content smoothly.

5. Community & Feedback: Engage players for feedback on expansions, ensuring new modules meet expectations and enhance replayability.

By focusing on these elements, developers can create arcade games that evolve with player demand while maintaining a cohesive and enjoyable experience.