This and Sonic 2 are the best Sonic Genesis games.
Sonic & Knuckles carries on from where Sonic the Hedgehog 3 left off. At the end of Sonic the Hedgehog 3, after Dr. Robotnik's defeat at Launch Base Zone, the rebuilt Death Egg fell back to Angel Island and crashed on top of Lava Reef Zone's volcano. Now the evil doctor attempts once again to repair the Death Egg, this time by trying to use the Master Emerald to fuel its engines. This all-powerful jewel, upon which the Chaos Emeralds base their powers, is guarded by Knuckles. In Sonic the Hedgehog 3, Dr. Robotnik was able to fool the echidna into working for him and against Sonic. In Sonic & Knuckles he betrays Knuckles in order to obtain the Master Emerald. Sonic and Knuckles then work together in order to stop Robotnik and save Angel Island. In this way Sonic & Knuckles resolves the feud between the two characters, and ties up the plot of Sonic the Hedgehog 3. Playing as Sonic is the first part of Sonic & Knuckles, and playing as Knuckles is the second half. Wow. Great Storyline. GRAPHICS- The graphics are in fact brilliant. The character designs are the same as Sonic 3 (I can barely find a difference). Now you think I would give the graphics a 9... WRONG! I'm giving them a 10. Why? Remember my review for Sonic the Hedgehog 3 for Genesis? I stated that the level designs and enemy design looked... well in my opinion lame but In this game, that problem was fixed. Sonic Team managed to improve the level designs and enemy design. Excellent job Sonic Team. Excellent Job. There are no retarded looking monkies or those constipaited rhinos. Thank god. The effects are plain awesome. Look at the explosions. Aren't those sweet? Now this is the best looking Sonic game on Genesis. The sheilds are the same... and yet their still sweet. The graphics look brighter and shinier than Sonic 3. Special Stage designs look great (cel shaded pshydo 3D graphics). The battle between Sonic and Knuckles looks pretty good! Okay. I'm busy complimenting the graphics. Is there a downside? Is there? Oh crap. I just woke Shorty up. Okay. I'll be right back kicking Shorty's @$$. 2 hours later.... Okay I'm back. Shorty's in pain (but not crying). Don't get mad at me. He deserved it. Anyway, now I'm sure you all know that this is among the greatest Sonic games of all time. Though the character designs are not the different from Sonic 3. Guess what? They still are great. Remember that please.
GAMEPLAY- Improved. And they get a 10. Storymode is great a lot. 2 characters so no spotlight stealing. Great. That's a pretty cool move. The boss fights rule. They're awesome to do and complete. The knight who throws wood at you looks plain cool. Boss' special abilties make a great challenge. Another great thing I'll have to say about Sonic & Knuckles is the Lock On- Technolgy. You can use a device that can make Sonic 2 and Sonic 3 get more features. Insert the device to Sonic 2 or 3, put the game cartridnge on the Genesis and BOOM! You'll get more features. The Lock On Technolgy actually made Sonic 3 be better. That was a great idea. The gameplay is overally perfect. And yet... this game is a masterpiece. However the speical stages aren't easy. It's almost impossible to complete. But it's still fun. But they're the same as Sonic 3. Seriously, the special stages should've been different. SOUND- Great music, Great everything, blahblah. OVERALL: Among the best Sonic games ever. This and Sonic 2 are the best Sonic Genesis games!