Fresh and interesting concept, great gameplay!
First off is the story mode that bases itself off a duo instead of individual characters that still gives off a different conclusion text depending on which of the two you chose first. You can also do a custom duo to play through with if you are uncomfortable with playing with a character you're terrible with as backup. *cough* Dhalsim *cough*.
The online mode is much like Street Fighter 4, with a set of flashy titles, points and your run-of-the-mill desire to brag as you beat your opponent senseless in a fair is fair brawl.
Finally, I'm amazed at the character colour design that allows you to pimp your character's costumes with a variety of colours that give your character the look you've always wanted.
My only beef with this game is the lack of boss variety. At the end of the day, you'll only encounter the same bosses depending whether you are a Street Fighter or a Tekken fighter and never take on any of the different fighters you may have missed in the mass struggle for Pandora's Box