Seaside Hill is the introductory stage for Team Sonic, designed to familiarize you with the core mechanics. It's a vibrant, coastal level filled with loops, springs, and basic enemies. Your primary goal is to reach the end of the stage as quickly as possible, collecting rings and defeating enemies along the way. This stage is relatively straightforward, but mastering the flow here will set you up for success in later, more complex levels.
Focus on maintaining your speed and utilizing Sonic's Homing Attack to chain together enemy destructions. Don't be afraid to experiment with Tails' flight to reach higher platforms or Knuckles' power to break through obstacles. The stage is linear, but there are often multiple paths, some leading to more rings or power-ups. Aim for a high ring count and a fast time to secure an 'A' rank.