Sonic The Hedgehog (World) (Proto) ROM

Some Sega Genesis/Megadrive games saw the light on their lower spec conterparts, the Master System and the Game Gear.
However, what saw the light in Sonic 1's case was not a direct port of the game but a whole new different experience, with low end graphics, but awesome gameplay.
The story of this one installment is the same as its 16-bit counterpart. Dr. Robotnik (Eggman in Japan) is up to no good, trying to dominate the world, so its up for Sonic the Hedgehog to foil his plans.
In this installment, the Chaos Emeralds are sparsed in the map, hidden in hard to reach spots. Get them all, finish Robotnik's contraptions and you can pat yourself in the back, being conquered a really hard but amusing game.
The main difference between this title and the Master System one is the screen resolution and the use of road signs to denote when there's a danger ahead. Also, the difference between this and the final version is the length of the game, as this is a prototype version most levels are broken or have serious bugs.

Sonic the Hedgehog (World) (Proto) is a game that was developed and published by Sega. Sonic the Hedgehog has to defeat Doctor Robotnik in order to save the world.

Sonic The Hedgehog (World) (Proto) is a game that was developed and published by Sega. This game features Sonic the Hedgehog and Doctor Robotnik. Sonic the Hedgehog must defeat Doctor Robotnik before the end of the war.