You say 6.4: about right I say. If Beatdown was poison this would be the antidote.
Graphics:7/10
The buildings and environments look very gray and repetitive. You never really feel like you're in a bright colorful place. But the lip-synching looks extremely good, and animations are well choreographed.Character design is very samey, but some models are taken into great care. The key characters look like they've been more looked into than the other ones.
Sound:5/10
As far as music goes, it's a mixed bag. All it has pretty much is rap and heavy metal. A few orchestral pieces play on the boss battles. Voices are also are mixed bag. While the tones of the characters are good (Kyle's deep voice fits him well) the actual dialogue isn't.
Story:5/10
The main character is Kyle Travers, brother of Cody. Cody was the main guy of the original Final Fight, but he retired from fighting a while back. After a few missions, Cody gets kidnapped in a bar brawl. You can tell what to do next.
OK, it starts off better than Beatdown because of the cool sounding voices, but afterwards it gets too darn stupid. I'd rather not spoil it, but let's just say it in one word: UNREALISTIC! You'll know what I mean.
Gameplay:8/10
Wow, a good fighting engine for a beat-em-up! There are 2 attack buttons plus a throw button. Unlike Beatdown, you can specifically target one enemy, and pull off directional button combos more easily that way. But it gets repetitive after a while, as you'd expect. Also there's no character customisation in this game, but that's a good thing, because in Beatdown, you had to do it to avoid the law. It made it clumsy.
Lifespan:6/10
The main story takes 6 or 7 hours to complete, which is good and bad. It means it's of course short so you may be wanting more, but it means you'll know that the repetitive action won't stray on for long, and makes you feel compelled to beat it. Replay value is much better than Beatdown. This time you actually keep skills and cash. Side missions won't be carried over, but you can't have everything.
Buy or rent?: Rent!
It's far too short to actually buy, but it makes for a fun night's play. As I said Capcom repaired their reputation with this game.