Collect all the rings during the ending sequence to see Sonic show his fist pump pose from the Sonic The Hedgehog 2 and Sonic The Hedgehog 3 ending sequence, or turn into Super Sonic if you also have all the Chaos Emeralds.
While at the in-game pause menu, press the following with the d-pad(directional pad): UP, DOWN, UP, LEFT, LEFT, RIGHT, RIGHT. A ring sound will confirm correct code entry.Exit the pause menu and you will be able to change into objects in the game.
ACHIEVEMENT - HOW TO UNLOCK The Story Begins (5 points) - Clear Splash Hill Zone, Act 1. Crush Dr. Eggman (5 points) - Defeat a boss for the first time. The First Chaos Emerald (5 points) - Acquire a Chaos Emerald. Enemy Hunter (10 points) - Defeat 1,000 enemies. Golden Flash (10 points) - Clear all Acts as Super Sonic. All Stages Cleared! (10 points) - Defeat the final boss and view the ending. Contender (10 points) - Upload your recorded scores and clear times for all stages. Ring Collector (15 points) - Collect all the Rings in 'Special Stage 1' and Clear the stage. Immortal (25 points) - Build up 99 or more extra lives. Super Sonic Genesis (30 points) - Acquire all seven Chaos Emeralds. Speed's My Game (35 points) - Clear Splash Hill Zone Act 1 in less than a minute. Untouchable (40 points) - Clear the E.G.G. Station Zone without taking any damage.
While at the in game pause menu, press the following with the d-pad(the directional pad):UP,UP,DOWN,DOWN,LEFT,RIGHT,UP. A chaos emerald sound will confirm correct code entry and unlock all Super Emeralds for the Hyper Sonic cheat code.While at the in game pause menu, press the following with the d-pad(the directional pad):UP,DOWN,UP,DOWN,LEFT,RIGHT,DOWN. An extra life sound will confirm correct code entry and unlock the ability to transform into Hyper Sonic when you collect 100 rings.
Play the Casino Street Zone and run through the level. Activate the "slot machines" to gain extra lives. After collecting the desired amount of lives, pause game play and leave the level to save those lives. Restart the level and repeat as desired.