I bought the game today on XBLA and i really like it ,But every now and then the sound and visuals start stuttering out and going weird. 
Just wondering if anyone else is having this problem?

Some levels are designed in that way. I hate to sound obvious, but are you sure it's not just the level you're playing?

I've been playing it for hours with my brothers on 360 and we haven't had any problems like that. That being said, we did freeze the game accidentally by doing some ridiculous combo.

Yeah, game's got some slow down issues. I had to restart my console after an explosion froze the game.

I played it for about an hour. I haven't noticed any problems as of yet.

Yeah, my console froze during the first level, had to restart obviously.

You know some of the visual jank is one purpose, right?

1) As many people have stated, some levels simulated pixel corruption like it's old dusty cartridge
2)Try clearing your system cache. 
3) Delete and redownload. 
 
Played for about 90minutes so far and no problems other using a character I didn't like too much.

Its frozen on me several times.  Also on the third boss battle the game music and visuals started freaking out.

I have read the PS3 shares the similar problems but it seldom happens.  Some said the music is out of sync or the whole game freezes.  As for me, the only problem I encountered was there was a part that didn't let me proceed to the next area so I just pressed Start then viewed the How to Play part then I went back to the game and the enemy that got stuck appeared. 
 
As for visual glitches in the subspace, those are intentional.  It pays homage to the cartridge games graphical glitches.

>_< its out?! oh god! *runs to download*

The game has frozen for me twice. Both times on the third level in front of the store.

Not much jank here other than occasional music slowdown after doing a long combo chain. The only other thing is that there is some lag when trying to open up the menus in the main overworld. Meh, still is a blast to play.

Me and my little bro played the PS3 version for hours upon hours and experienced a few freezes and only some slow down (though again, this was a common place in old beat 'em ups, and seems intentional at some point).  For the most part, the freezes happened soon after starting the game, so it wasn't as if we'd been playing for hours and then the game froze.
Just DL'd the 360, but haven't gotten a chance to play as of yet.

The PS3 version had none of the problems people are saying.. for me atleast.... so I guess it's something with the 360 version... 

This shit with the menus in the store caused me to stop playing the game..

I am glad to hear it is just a problem with the game and not my box.  I hope they patch it soon.

I never froze really.  The problem I was having is akin to a CD skipping, it just freezes for a moment and I can really only tell because of the sound.  It didn't effect my game play so I assumed it was intentional like some of the other effects in the game.

I have a 360 Slim and have played this game for hours with no problems.

I had a hard lock during the first level (just after the snowball fight). I haven't gone back to play since my download of Shank just finished. 
It's sort of a bummer that XBL is getting a lame duck version.

" You know some of the visual jank is one purpose, right? "

My 360 froze twice. I feared the RRoD while playing this game. I'll play it again once a patch come out.

I've not seen any problems at all.   Just having control issues with the not-so-great d-pad.

it froze on me once after i defeated gideon on his second form :< i beat it now thoug except i did it with stills so no achievement

It's totally locked up a half dozen times on me, the main trigger seems to be hitting objects in the environment and letting them bounce around. Once I intentionally avoided interacting with items other than picking up weapons, and I took care to only hit items and not objects, I was fine.

" It's totally locked up a half dozen times on me, the main trigger seems to be hitting objects in the environment and letting them bounce around. Once I intentionally avoided interacting with items other than picking up weapons, and I took care to only hit items and not objects, I was fine. "

Demo has frozen on me twice and I had a section where the screen wouldn't scroll (Luckily, the guys on the next screen spawned and just walked over to my side.  I defeated all of them and the screen started to scroll again).  Definitely want to buy this game, but I'll hold off until a patch comes out.
 
On a side note, is it just me or is this game difficult?  I can't beat the demo level on medium difficulty.  Blocking is pretty much non-existent in the demo.  Does that change as you progress your character?

I heard a ton of complaints on other boards about freezes etc on PS3, so I knew to expect it. 2 freezes so far in 4 hours.

I got the demo for PS3 and it froze while loading the story mode from the main menu. I deleted it shortly after. I have no patience for serious game faults on a closed platform. Very shoddy optimization.

I've had the music stop working. 
 
If you're having lots of stuttering, do you have a ton of activity in your friends list?  Try disconnecting your network and see if that affects it.

I've had tons of slow down, and on multiple occasions the game will lock up my 360. I cannot get past the 3rd stage because of this. Here's hoping there is a patch in the works!

Glitches I've encountered thus far:
 
Music not tuning in until an entirely new area is loaded
Game crashes (freezing)
Players disappearing entirely instead of respawning for minutes at a time (happened during the first fight against Gideon)
 
Aside from freezing, which happened three times over the course of a whole playthrough (one was pretty infuriating, since it was in the final area of the final level), the others have only happened once. Hopefully a patch will come out that fixes some of these problems, since they appear to be pretty widespread.

I had a weird problem today. I was on the 4th stage, with the ninjas, about half way through the level there's a screen with 3 holes in the floorboards, I got kicked by a ninja into one of these holes. I assumed I was going to lose some HP and respawn but I didn't, I was stuck under the floor, I couldn't move but when I pressed the attack button I could hear that I was doing them, I was able to call in the striker to do damage but was unable to get out so I had to quit.

I just got the game last night and was playing for about 40 minutes or so when it crashed. I played another game, without flaw, and decided to come back to Scott Pilgrim. When I started it back up I noticed that despite the game saving a couple of times, it couldn't find anything. I guess it was corrupt. I started over and it froze 15 minutes in. I think I'll wait for a patch before continuing.

I've had random freezes (always on the train level), I've had pigs in the bonus stages flash into and then out of existence and I've even had Todd Ingram's boss fight pic reappear halfway through that fight. There's also several cases of just sloppy programming such as if you start at the Shopping District, the music won't start for a while. If you then go into a shop, both the shop music and level music will start playing at the same time. Not to mention to more common things like various menus taking a while to appear.

I've had the 360 version completely lock my system 3 times in the last two days since I bought it.  I had one or two quick pauses, but having to actually get up and turn the system off is frustrating.  Maybe it is just me about to get ANOTHER RROD, but maybe not.

Is there ever going to be a patch for this game,or they to busy throwing out premium XBL themes ? : / 

Don't forget the avatar costumes! I bought the Ramona one but it kind of sucks because none of the haircuts or hair colours are anything like any of hers. But yeah, a lot of care and attention was put into this game on the graphic and sound design side of things, it's a shame for them to leave it so lacklustre from a glitchiness point of view.

It froze on me once on the second stage. Didn't happen again, thank goodness.

I get some random freezes but I'm more ready to blame my old Xbox than the game.