A beat'em'up with characters taken from many Capcom and SNK games. The game system is centered around "grooves" which are selected before any battle. These different grooves alter the character's abilities to resemble different Capcom or SNK games. There are three grooves dedicated to each company, and even the option to define a custom groove.
The "EO" of the GameCube and Xbox titles refer to a new groove: Easy Operation. Instead of the normal inputs needed to do special and super moves, these moves are instead done automatically by tapping the right thumb-stick in specific directions. Only a small part of each character's move set can be accessed this way, however, and if the player does not select EO then the game will play the same as the arcade and previous releases.
Playable characters come from the following games:
The EO (Extreme Offense) edition of Capcom vs. SNK 2: Mark of the Millennium allows the player instant access to certain special moves using the second analog stick of the controller. Therefore, it's an easier edition for beginners to get into the series (although it can be turned off at any time for experienced players).