I know it's early to start thinking about a second installment but I feel there were a lot of missed opportunities here. There are a lot of things that this game could have borrowed from other sony exclusive titles but didn't, and other things that would just make the game better as a whole.
Cinema mode - Being able to look at matches we've played... if every shooter in the world can do it, and even a wii game can do it, PSASBR should be able to do it.... I'm doubtful we'll ever get to this point, but it'd be nice to be able to record clips or full games and post them on the net the way Uncharted 3 does it (but having the "save to XMB" is really handy too). Oh yeah, and being able to take pictures
Customizable backgrounds - Really surprised we couldn't just pick our favorite characters to be our backgrounds.
Permeable team mates - How about we pass through our team mates? I find it very annoying you can pass through a lot of things easily but one wrong move and you miss a super due to your team mate having mass, while the other characters don't.
Better menu scheme - Not only does it look boring, but it doesn't keep up pace with other sony exclusives. Uncharted, god of war, starhawk all have hugely dynamic menus when online, but PSASBR only has a background, with a boring menu layout. Even the character select could look a little better.
Better player cards - great idea, with lots of customization but lets be honest here....the icons look like SD google images while others look weird (all of raidens look weird, though I don't have him very high level yet) and the backgrounds look nice, but some of them are really weird, like it's a image but zoomed into a weird spot. Combine all of these with the karate belt and possibly the titles for online and you've got one hell of a cluster F***.
Greater character balance - Not only with supers but with standard attacks and AP gain. Some characters gain AP and do tons of supers each match, while others have to grind to get their AP. The attacks are weird... giving heaps of AP to certain attacks and encouraging spam, while a lot of attacs per character give barely any AP what so ever. Supers are odd... characters like Sly never need more than a level 1 because it's completely unavoidable, fast and covers a huge area. This should be the opposite. Level 3s should always be the best, reaping the most rewards but also, comes with a great risk such as running out of time and not being able to get it off.
Clashing supers - Every once in a while you have two people activate supers and it's almost like the game has no idea what to do. I'd say a good idea would to have these supers "clash" where one would have to push a button really fast or spin the analog stick or something in order to gain "power" over them and over ride their super.