Beat 'em ups don't get any better than this.
The basis of the game? Punch, kick, throw, and bash everyone on screen to progress. It's primitive, yes, but undeniably fun. You can pick up any item laying around on the streets or any weapon a foe you just beat down was brandishing, and continue the smack down. Each character (there are 3 of em, balanced, but different) has their own move set, speed, damage, specials, etc. Speaking of specials, these moves are done in desperation attempts at the cost of some life. They're powerful, but you certainly can't rely on them.
Streets of Rage 2 rates up their with the best Genesis games, including Gunstar Heroes and the Sonic the Hedgehog series. If you're looking to extend your Genesis collection, you need this game.