Designing arcade games for spectator appeal requires a blend of engaging mechanics, vibrant visuals, and interactive elements. Here are the most effective strategies:

1. Dynamic Game Mechanics: Fast-paced, easy-to-understand gameplay keeps spectators hooked. Simple controls with deep skill ceilings allow both casual viewers and hardcore fans to appreciate the action.

2. Stunning Visual Effects: Bright colors, flashy animations, and exaggerated physics make the game visually exciting. Spectators are drawn to eye-catching details and fluid motion.

3. Multiplayer Interaction: Competitive or cooperative multiplayer modes create drama and tension, encouraging spectators to root for their favorite players. Leaderboards and live commentary enhance the experience.

4. Clear Spectator UI: A well-designed spectator interface highlights key moments, scores, and player stats, making it easy for viewers to follow the action.

5. Replay and Highlight Features: Instant replays and shareable clips allow spectators to relive epic moments, increasing engagement and word-of-mouth promotion.

By focusing on these elements, developers can create arcade games that captivate both players and audiences alike.