Sega released Sonic the Hedgehog 3 for the Mega Drive and Genesis in 1994. After the Death Egg crashes onto the floating Angel Island, Dr. Robotnik tricks the island’s guardian, Knuckles the Echidna, into believing that Sonic and Tails are the real threat. This is Knuckles’ first appearance, and he repeatedly ambushes the heroes throughout the adventure. The game introduced three elemental shields – fire, water bubble and lightning – each with its own dash or bounce ability, and Tails can now fly and carry Sonic when playing together. Zones such as Hydrocity, Carnival Night and IceCap are larger than in earlier games, with multiple routes through each act and bonus stages hidden in giant rings. A battery save lets players continue their progress. Sonic 3 was originally conceived as one larger game, and its second half was released later that year as Sonic & Knuckles, which can be joined with Sonic 3 to form the complete story.