I just wish I still had my genesis and my original Sonic The Hedgehog cartridge unfortunately it's in Gyro's hands now. 
I hope you treat my baby well Gyro lol. Anyhow, onto my full review. And if I have any spelling and/or grammatical errors please excuse me because this is a long and tedious review down to the last detail. Enjoy! Storyline: 9/10
As the very first of all Sonic games there to be honest wasn't really much of a storyline to follow through with this game. All it pretty much was, was a speedy blue hedgehog is fighting off a tyrannical lunatic madman scientist going by the name of Dr. Robotnik (Dr. Eggman in Japanese) who has besieged his homeland on the Southern Island entrapping all the little critters (Flickies) into evil badnik robots in proclamation of world domination. It of course would make sense since nobody even knew how well this game was going to sell to continue the series off to add more storyline development. Despite it being a brief storyline it's actually what I like about this game. Just like Sonic it's a speedy storyline getting straight to the point. (Kick Robotnik's butt)
Graphics: 9/10
If you were to go by a gamer's perspective going back in time with the very first release of this game onto the Sega Master System platform, this was actually an amazing technological feat. The release of this game made even Nintendo quack their boots about this game. Not only did this game boast superior graphical capabilities but, it even provided a much faster speedy sense of gameplay. You could feel yourself in Sonic's shoes zipping through the levels smashing through the badniks with ease with a sense of accomplishment at the end of every level. The high detailed luscious background scenery and all of the greenery in the beginning stages and the starlit sky and the wacky casinos helped to give a much better sense of the environments you were in. It's a true nostalgic classic to behold.
Music/ Sound affects: 9/10
This game not only packed heat in the graphics department but also held up really well with the music and sound affects as well. You can notice a huge revolutionary change from the primitive 8-bit Mario games to this newfangled 16 bit game's music and all it has to offer. I even occasionally found myself whistling Green Hill Zone and I love the sound affects as Sonic smashing his way through the badniks and zipping past the finish line at the end of every act.
Gameplay/ Replay: 9.5/10
I save the best for last!! We can now get down the real deal that gave this game it's name and made Sonic just what Sonic is today. The gameplay! This game has captured so many people's hearts seeing their speedy blue hero as he zips through every level smashing and destroying everything on the screen and they get the feel of his speed as they zip through all the loops seeing as the scenery passes by. This game has truly outdone itself with it's heavy set of gameplay and a large sense of accomplishment as you finish the game. I also feel it holds strong on the replay-value as it's just as fun EVERY time whenever I play this game again, and again, and again.
Overall: 9.5/10
I definitely give this game an A+ without moment's hesitation. This game gives you everything a speedy gamer wants. A fast straight to the point game with nothing but intense action. This game was truly both revolutionary and legendary. If you haven't played this game yet I highly recommend you do so. Your in for a helluva time! ^_^
