Sonic MeGaDrive

Sonic MeGaDrive (codenamed Sonic Overdrive.) is a ROM Hack of Sonic The Hedgehog CD developed by Fred Moreau, featuring new zones, enemies, music, sprites, and story. The game also was revamped to be similar to the other classic Sonic games, the time travelling being removed from the game.
== Story ==
Some time after the events of Sonic The Hedgehog 3 & Knuckles, a strange island appears, a large silver orb on it. Detecting incredible energy radiating from the island, Sonic and Tails set out for it, wondering what may lie on the island.
When Sonic reaches the island as Hyper Sonic, he is immediately robbed of his "Hyper" power by Metal Sonic, who flies off afterwards. Suspecting Robotnik's involvement, Sonic and Tails go after Metal Sonic, hoping to find Robotnik's whereabouts.
== Characters ==
Character 	Description
 	The fastest thing alive. He comes to the strange island in search of the incredible energy there, only to be attacked by Metal Sonic!
 	Sonic's friend, and an expert at mechanical knowledge. He pilots the Tornado, as well as an Eggmobile.
 	Sonic's robotic doppelganger. He was improved to knock the "Hyper" right out of Hyper Sonic, and now he can got faster than Sonic, too!
Doctor Ivo Robotnik	After the events of Sonic The Hedgehog 3 & Knuckles, Robotnik's lower body was replaced with a "better" robotic body. He's up to his old tricks again!
== Zones ==
	
	After watching Metal Sonic steal the Chaos Emeralds, Sonic & Tails head off to see what lies ahead. The Miniboss is an abandoned EggRobo.
	A storm descends upon the island at night, causing waves, lightning, and falling trees. The Miniboss is a Venus Flytrap.
	A boss fight against Robotnik's Egg Shocker. Afterwards, Sonic & Tails leave in the Tornado, but are blasted out of the sky by Metal Sonic.
	
	After getting blasted out of the sky, Sonic & Tails advance into the glade after Metal Sonic. The Miniboss is one of Robotnik's robots.
	Sonic & Tails proceed into the ruins of an ancient race, and find many traps as rain starts to fall. The Miniboss is an EggRobo boss fight identical to Knuckles' Marble Garden boss fight in Sonic The Hedgehog 3.
	A boss fight against Robotnik's Egg Drill. Afterwards, Tails flies Sonic to the next Zone.
	
	Sonic & Tails arrive on a coast, and traverse through a coral reef and onto the beach. The Miniboss is one of Robotnik's robots.
	Sonic & Tails arrive at the amusement park, with waterslides and the like. The Miniboss is Knuckles The Echidna.
	A boss fight against Robotnik's Egg Submarine. After the battle, Sonic & Tails, as well as Knuckles, get blown away by the explosion the Egg Submarine creates.
	
	Sonic snowboards down into the cavern a la Ice Cap Zone, and ends up in the deep innards of the Zone. The Miniboss is Big Icedus from Sonic The Hedgehog 3.
	Sonic adventures through the cavern to find Knuckles & Tails. The Miniboss is one of Robotnik's robots.
	
A boss fight against Robotnik's Egg Pump. After the battle, Sonic & Tails chase Metal Sonic onto Flying Battery II, which leads to the next Zone.
	
	After ending up on the underside of the ship, Sonic & Tails try to make their way up to the interior. The Miniboss is Gapsule from Sonic & Knuckles.
	Sonic & Tails make their way into the interior, and wreak havoc on it. The Miniboss is similar to the Wing Fortress Zone boss from Sonic The Hedgehog 2.
	A boss battle against Robotnik's Hang Mobile. After the battle, Metal Sonic throws Sonic & Tails off the ship.
	
	Sonic & Tails land in the reconstruction site of the Death Egg, and destroy the reconstruction site. The Miniboss is Swing'm Spikes from Sonic The Hedgehog 3.
	Sonic & Tails go through the remains of the reconstruction site, as well as some of the jungle surrounding the area, and eventually get into the Death Egg itself. The Miniboss is Red Eye from Sonic & Knuckles.
	A battle against Metal Sonic, and, if Part 2 has not been downloaded, Big Arm from Sonic The Hedgehog 3 as well. If Part 2 has not been downloaded, the game ends here. If it has, Sonic & Tails take a teleporter to the next Zone.
	
	Sonic & Tails land in a design studio-esque city, a la Studiopolis Zone. The Miniboss is Mecha Sonic from Sonic & Knuckles.
	Sonic & Tails advance into the dark alleyways of the city. The Miniboss is one of Robotnik's robots.
	A boss fight against Robotnik's Egg Dancer. Afterwards, Sonic & Tails board the Flying Battery II as it passes by outside.
	
	Beginning the same as the original Flying Battery Zone from Sonic & Knuckles, Sonic & Tails progress along the inside and outside of the ship. The Miniboss is similar to Big Shaker from Sonic The Hedgehog 3.
	Sonic & Tails advance along the inside of the ship and eventually reach the front of the ship. The Miniboss is Metal Sonic.
	A boss battle against Robotnik's Egg Biplane as the ship falls apart. After the battle, Sonic & Tails flee the ship as dusk falls.
	
	Sonic & Tails land in a mineshaft, and work their way out. The Miniboss is EggRobo using the Egg Drill from Sonic The Hedgehog 2.
	Sonic & Tails find Knuckles in the jungle on the mountain, and try to find a way to escape with him. The Miniboss is Flame Craft from Sonic The Hedgehog 3.
	A boss battle against Robotnik's Flame Mobile from Sonic The Hedgehog 3. Afterwards, Sonic, Tails, & Knuckles advance to the mountain up ahead, where Robotnik's base is.
	
	Sonic & Tails advance towards the Death Egg, while Knuckles goes off to find Robotnik. The Miniboss is Metal Sonic.
	Sonic & Tails chase Robotnik through the canyon in an Egg Mobile in a race. The Miniboss is Metal Sonic.
	A boss race against Metal Sonic, who turns into Super Metal Sonic from the player's Chaos Emeralds, as well as, if all Chaos Emeralds have not yet been collected, his own. Metal Sonic is destroyed at the end of battle, as Sonic chases Robotnik into his spacecraft.
	
	Sonic, Tails, & Knuckles all reach the Death Egg, and get through various traps both inside and outside the ship. The Miniboss is EggRobo powered up with a Super Emerald.
	Sonic & Tails destroy the necessary parts of the Death Egg on the inside as Knuckles destroys the outside. The Miniboss is Red Eye from Sonic & Knuckles.
	A boss battle against the Robotnik's Z-11 Mech. After the battle, if all Chaos Emeralds (as well as Super if Part 1 is locked on.) have not been collected, the game ends here. If they have, Sonic transforms into Super/Hyper Sonic and goes after Super Mecha Sonic.
	
	Sonic chases down Super Mecha Sonic and destroy it. This is the ending of the game in both the locked on and singular versions.
== Robot Race ==
After completing the main game, a new mode called Robot Race opens up. Robot Race is focused on going through one Act of the game at a time, racing against Metal Sonic. Like in the 2011 remake of Sonic The Hedgehog CD, there are rewards for getting a low time;
Under 0'40"00	Unlocks Sonic MeGaDrive's Digital Audio Garden.
Under 0'35"00	Unlocks Sonic MeGaDrive: Episode K.
Under 0'30"00	Allows the Special Stage courses to be played at any time.
Under 0'25"00	Unlocks the Visual Mode; which allows the player to see the opening and ending cutscenes.
Under 0'20"00	Unlocks the complete Sound Test with included Easter Eggs.
Under 0'15"00	Tells all the codes to the Easter Eggs in the Sound Test.
Under 0'10"00	Unlocks Sonic MeGaDrive: Episode Metal.
Under 0'05"00	Halves the amount of rings required for Super and Hyper forms.
Under 0'01"00	Allows the characters to go Super or Hyper at any time, if they have all Chaos/Super Emeralds.