Achieving a high score and accumulating extra lives are key aspects of mastering Sonic & Knuckles. Here are some tips:

- Collect Rings: Every 100 rings collected grants an extra life. Always prioritize collecting rings, even if it means taking a slightly longer path.
- Speed Bonus: Completing an Act quickly awards a significant time bonus to your score. Practice routes to optimize your speed.
- Destroy Enemies: Each defeated enemy adds to your score. Try to defeat as many as safely possible.
- Bonus Stages: Always aim to enter Bonus Stages (by passing a Star Post with 50+ rings) as they are excellent sources of rings and extra lives.
- Perfect Special Stages: Completing Special Stages by collecting all blue spheres without touching any red spheres awards a substantial score bonus and an extra life.
- Ring Retainment: If you get hit and scatter your rings, quickly try to recollect as many as possible. This prevents you from losing a life and helps maintain your ring count for extra lives.