It's a 4 players competitive party game. The game consists of 4 types of events which you can read about
here. There are tons of quirky details, moves and secrets to discover each time you play.
The differences between the NES version and the PS3 port are:
+ new unlockable teams and trophies
+ improved controls
+ balanced scoring system (you get penalized for attacking now as opposite to being rewarded points in the NES version)
+ extensive and detailed lists of moves and characters bio
+ nicely made menus
+ online play and easier access to 4 players
+ well done translation
- the backgrounds have more details now but the graphics used look cheap
- gameplay is a bit slower