Genre: Football (aw wait, let me specify: European football, which is American soccer or what? WHERE YOU KICK THE BALL WITH YOU FOOT GODDAMIT)
Graphics: Good. Funny effects, but not that much that you aren't able to grasp what the hell is going on on the screen.
Story: It's a fantasy-football-game. There is none. Teams play against each other. Each team has one captain, which is always one of the more iconic figures of nintendo, like bowser, mario, peach, waluigi and so on, and 3 team members, which are side-characters like koopas or drybones.
Every ingameplayer has different stats, some are slow but shot really hard, some are very good at getting the ball and passing, and so on. You can freely choose your team.
You can foul, you can do tricks, you can do hilarious cool shots, you can use items which spawn after good shots or fouls by your enemy.
It's much fun, go out and play it. Even better if you have a buddy who is also on your skill-level.