Level select:To unlock level select, press UP, UP, DOWN, DOWN, UP, UP, UP, UP after the Sega logo fades and Sonic appears, and before the screen flashes white. Press UP at the title screen to access level select.Extra lives:Set off the first alarm on the first level of the Launch Base Zone. Wait in the middle of the alarm and perform Spin-Dash attacks on the Flybots. The value of the Flybots will gradually increase to 10,000 points as they continue to attack. Accumulate points and lives at this location.Sonic And Knuckles music:In the 2nd Zone and 3rd Act, before fight Dr. Robotnik, allow your character to almost drown, then put your head back up in air to hear Sonic and Knuckles music.Speed boost:To receive speed bost,? jump when Sonic is just over halfway on the loop.Easy rings:On Act 3 of the Icecap Zone, turn into a ball at the end before you reach Robotnic and fly off a ramp onto a purple trampoline. Look up to see a large number of rings. Bounce high to find another set of rings. Go to the right to find a big ring.Achievements:ACHIEVEMENT – HOW TO UNLOCKComplete the Game (25 points) – Finish the game.Fast Freeze (25 points) – Complete the Icecap Zone.Complete Chaos (25 points) – Collect all seven Chaos Emeralds.Points III (25 points) – Score 80,000 points.Marble Finishes (15 points) – Finish the Marble Garden Zone.Wet Feet (15 points) – Run across water.Wet and Wild (15 points) – Finish the Hydrocity Zone.Points II (15 points) – Score 40,000 points.Chaotic (10 points) – Collect a Chaos Emerald.Halfway there… (10 points) – Collect 50 rings.Goodie Gumballs (10 points) – Get a blue gumball.Points I (10 points) – Score 20,000 points.