I'm not really against restrictive demos--after all, the whole point is to give you something to see before you make the call on buying it or not, not to give you something so fully featured that you won't bother buying the full version. That said, not including any kind of single-player is a hassle if you're the sort of person who doesn't get into local multiplayer very often. I had to dig around in a box of broken controllers to find my other PS3 controller just so I could see what the different graphical modes look like.
The good news is that once you find that other controller and come to terms with the weird gunk that has collected around the D pad area, you can sit on the handicap and stage select window for as long as you like while the character select music loops forever and ever. You know, now that I've been sitting here listening to the game shout "WANNA TAKE YOU FOR A RIDE" at me for the last 10 minutes or so, I'm starting to hear the hidden depth in the song. I'm pretty sure it's telling me to murder some foreign heads of state. It's the only way I'll ever get Anna Paquin to notice me! You're right Song, I'm going to need more swords!
Once you're done receiving hidden instructions from our dark overlord, the game has you select your three-man team and get in. I always thought that MVC2's 2D sprites on top of polygonal backgrounds looked a little odd, and having all of those 3D background assets blown up into something bigger and better looking than the original release sort of makes the mix of sprites and polygons stand out even more. You can sort of mitigate this by applying a couple of sprite filtering options that smooth things out in different ways. I've always liked my sprites to be as raw and unfiltered as possible, though, so I think I prefer the "classic" option, even though those look the weirdest when set on top of the new, smooth-looking backgrounds.
Anyway, I mostly wanted to warn you about the game's two-player requirements, in case you don't have anyone nearby who wants to play with you and you aren't the type of person that gets off on beating down empty controllers. Even still, if you want to see the graphical filtering options for yourself, this demo certainly lets you do that.