Some time after his first adventure, Sonic CD opens with Sonic rushing to Never Lake, where an extraterrestrial body, Little Planet, appears in the last month of every year. The game also includes a save feature, which uses the back-up memory of the Sega CD. Garden', where players can listen to the music of completed zones and a 'Visual Mode', where players can view the opening and closing animations. The game also features a time attack mode, where players can replay completed levels for the fastest time possible a 'D.A. Collecting all seven Time Stones automatically creates a good future in every zone, unlocking the best ending. If the player destroys all the UFOs before the time runs out, they earn a Time Stone.

Time is reduced swiftly if the player runs through water, though a special UFO which appears when time is running out grants extra time if destroyed. īy finishing a level with more than 50 rings, Sonic can access a special stage, in which he must destroy six UFOs in a pseudo-3D environment within a time limit. Achieving a good future in every zone unlocks the game's best ending. To achieve a good future in each zone, players must travel to the past and destroy a hidden transporter where enemy robots spawn. By default, future stages are neglected and littered with machinery after Robotnik has conquered the Little Planet, appropriately named 'bad futures.' Players are encouraged to convert each zone into a 'good future', with bright colors, thriving nature, and few enemies. He travels through time by hitting signs labelled 'past' or 'future', maintaining his speed afterward. The third zone is always set in the future, its timeline dependent upon whether the player destroyed both transporters.

Sonic starts the first two zones in the present. The music changes within the different time zones, as remixes of the present music. Sonic CD is differentiated from other Sonic games through its time travel game mechanic, which allows players to access different versions of rounds set in the past, present and future. Players start with three lives, which are lost when they suffer any type of damage without rings in their possession losing all lives results in a game over. Each round is split into three zones, the third of which ends in a boss fight against Robotnik. In the first and second games, the levels were named zones, but in this game, they're named rounds, the previously-named acts now named zones instead. Sonic can also perform a 'spin dash' and a 'super peel-out', both of which increase his speed. Like previous games, Sonic can destroy enemies and objects (such as certain walls and television monitors containing power-ups ) by rolling into a ball, and collects rings as a form of health. Players control Sonic the Hedgehog as he ventures to stop his nemesis Doctor Robotnik from obtaining the magical Time Stones and conquering a Little Planet. Sonic CD is a side-scrolling platform game similar to the original Sonic the Hedgehog. ( Clockwise from top left) The past, present, good future, and bad future variants of the Palmtree Panic level A remake, developed by Christian Whitehead using the Retro Engine, was released for various platforms in 2011 and rereleased as part of the Sonic Origins compilation in 2022. Sonic CD was ported to Windows as part of the Sega PC brand in 1996, and to the PlayStation 2 and GameCube as part of Sonic Gems Collection in 2005. It sold over 1.5 million copies, making it the bestselling Sega CD game. Reviewers praised its size, music, and time travel feature, although some felt it did not fully use the Sega CD's capabilities. It received critical acclaim and is often called one of the best Sonic and platform games. Two soundtracks were composed: the one featured in the Japanese and European versions was composed by Naofumi Hataya and Masafumi Ogata, while the one in the North American version was composed by Spencer Nilsen, David Young, and Mark Crew. Sonic CD features the debuts of the recurring Sonic characters Amy Rose and Metal Sonic, and includes animated cutscenes. Led by Sonic 's co-creator Naoto Ohshima, the developers sought to show off the technical capabilities of the Sega CD. Sonic CD began as a port of the Sega Genesis game Sonic the Hedgehog (1991), but developed into a separate project. By traveling through time, players can access different versions of stages, featuring alternative layouts, music, and graphics. Sonic CD introduces time travel as a game mechanic. Like other Sonic games, Sonic runs through themed levels while collecting rings and defeating robots. As Sonic the Hedgehog, the player attempts to protect an extraterrestrial body, Little Planet, from Doctor Robotnik. Sonic the Hedgehog CD is a 1993 platform game developed by Sega for the Sega CD.

Sonic cd soundtrack jp vz us