Sonic's offensive strategy primarily revolves around his Spin Attack and Spin Dash. Most enemies (Badniks) can be destroyed with a single hit from either of these moves. For flying enemies, a well-timed jump is usually sufficient. For ground enemies, a Spin Dash is often safer and faster. Remember that while in a spin, Sonic is invulnerable to most direct enemy contact, but not to environmental hazards like spikes or lava.
Defensively, rings are your primary form of protection. As long as you have at least one ring, a single hit will scatter your rings instead of costing you a life. Always try to collect as many rings as possible. The Shield power-up provides an additional layer of defense, absorbing one hit before disappearing. Invincibility is the ultimate defensive power-up, making Sonic immune to all damage (except drowning) for a short period. Knowing when to prioritize collecting rings or power-ups can significantly impact your survival, especially in later, more challenging zones.