Some impressions I got playing the story mode.
-Inconsistent and long load times. I went to warm up some dinner (2-3 minutes), and when I came back the game was still loading! Going into the next area also triggers loads but they are not as long.
-Horrible voice acting (during the cutscenes only). That and the frightfully neon costumes scream out 'SEGA!'
-Seemingly limited moveset. There is only one attack button (beat attack) in addtion to the special charge move, unless you switch to beginner mode. Otherwise you have to somehow utilize the thumb twisting X+Y and B+Y combinations. Streets of Rage actually seems deeper in terms of moves, but then again I'm still playing round with it
-Intentionally cheap check points. I say cheap because, they make you sit through at least 3 loads and 2 cutscenes without hitting a checkpoint on the first level. That means if you die, you start from the beginning. They must've followed the DMC3/ Ninja Gaiden school of level design.
-Overall, I think it is a fun game, but not quite worth the 30 bucks I paid for it. YMMV, especially if you plan to play with friends or on XBL. The split screen is kind of blurry with 2+ people playing, but I can see how it would be fun. I couldn't find any people playing online as of yet to test out the XBL functionality.
I will probably get some friends over my house this weekend to get some co-op going. I can make a better judgment about the game then.