Sonic the Hedgehog is a video game created by SEGA, and Sonic Team. In 1991, the first game, Sonic the Hedgehog, obviously, was made. It did pretty well, for the Sega Genesis. Three other sequels were made, Sonic the Hedgehog 2, Sonic the Hedgehog 3 and Knuckles, and Sonic the Hedgehog 4: Episode I and II. Each game was a commercial success. The character, is also Sega's Mascot, replacing Alex Kidd.
You're basically just a blue hedgehog, saving animals from the evil Dr. Robotnik. It's up to you to save world domination from him. The main part about it is platforming and speed. You use the D-Pad and the A, B, and C buttons to run around and jump. You can also use the spin roll, which can break walls, and immedietly destroy enemies. Animals also come out of the enemies, and you get a point bonus for defeating them. Speed, is also needed to fully enjoy the game. The faster you go through the goal ring, the more points you get. You can get atleast 50,000 points.
There are also a few zones in the game. Seven are in the game. Green Hill Zone, Marble Zone, Spring Yard Zone, Star Light Zone, Labyrinth Zone, Scrap Brain Zone, and Final Zone. Green Hill is a zone where you learn the basics, and it really shows what the Genesis is capable of. Marble Zone is the second zone, and it is pretty slow. You can get hit lots of times if you're not fast enough. Spring Yard Zone is both slow and speedy, and basically, it's like Green Hill Zone, but less cheerful. Star Light Zone has mainly stars and speed. Think of it as Green Hill Zone and Spring Yard Zone, but with a faster pace. It's also pretty easy for a fourth level. Labyrinth Zone, is a water level. Sadly, Sonic can't breath in water, so within a few seconds, you'll drown, losing one out of your three lives. There are also many spikes, so be sure you have rings to survive if you're not that great at this game. Next, is Scrap Brain Zone. It's basically an entrance to Final Zone, where you face Dr. Robotnik, the final time in this game. It's also pretty half difficult, but you'll have rings to survive. Finally, is the Final Zone. You have no rings, there are a few things you must avoid, and you must hit Dr. Robotnik as soon as possible. Once that's done, you'll see our blue hero running through Green Hill. If you had each emerald, then the good ending would unlock, which does really nothing. In the end, however, if you didn't, you'll just see the evil doctor juggling the emeralds. That's basically all what Sonic the Hedgehog is.
To summarize it up, you have to save the world, get emeralds, defeat the doctor, run through stages, and collect rings while defeating robotic animals. It's a game worth buying, you can get the game for about 5 dollars on Amazon or so.