It's always fun to take characters from different universes and toss them all together. In SNK vs CAPCOM, you have primarily King of Fighters vs Street Fighter.
The first thing you see in a game is its graphics, and unfortunately the graphics here are pretty old school. You would expect that the XBox would have stellar - or at least current - graphic quality. But the character portrayals, movements, special effects and backgrounds are extremely ancient looking. You could easily mistake this for a game from the 90s.
The sound falls into the same category. You have very cheesy music selections with pretty unrealistic sound effects. You could say that it gives you the "arcady" feeling, but it wasn't even that well done.
I want to say here that I normally really enjoy playing "old school games". I grew up with Adventure and Zork, and will gladly play even text adventures that are fun. But this just wasn't that much fun.
While Amazon normally keeps old games stocked for years and years because they are still fun to play, this title was yanked off the Amazon shelves less than a year after a release. There's a reason why. Rent if you must, and see if it's something you'd enjoy keeping.