Route 99 is the first zone in Sonic Advance 3, serving as an introduction to the game's mechanics and level design. It's a relatively straightforward zone, but still offers opportunities to practice your tag-team abilities and explore. The environment is a bustling city, featuring plenty of loops, springs, and grind rails.
Focus on maintaining momentum and using your partner's abilities to reach higher platforms or clear groups of enemies efficiently. This zone is an excellent place to experiment with different leader/partner combinations to see how their unique skills interact with the level layout. look for hidden pathways that often contain extra rings or power-ups.