From Nintendo Power:
"To go along with the new touch-screen controls is a gameplay enhancement that takes advantage of the N3DS system's gyro sensor. Holding the system flat forces the camera into a mostly overhead view of the court - typical for tennis games. If you put the N3DS in a vertical position, though, the camera shifts behind your character. From this point of view, you aim your shots by simply moving the system left and right. While playing in this Dynamic View mode, your character will automatically run to where the ball is approaching, leaving you free to choose your shot and aim it properly. Not having to worry about reaching the ball means casual players will especially benefit from this mode. It's also worth mentioning that the N3DS automatically turns off its 3D capabilities while in Dynamic View, as the frequent movement of the system would disrupt the stereoscopic effect."
There are 13 characters available at the start of Mario Tennis Open. Each one has a special attribute that will affect how you play as him or her. The information here will help you pick the character that's best for you.
ALL-AROUND
Beginners will want to start with these characters. They have no particular strengths or weaknesses, but they're well-balanced and easy to control.
EXAMPLES: Mario, Luigi
TECHNIQUE
These characters have great control over the ball, allowing them to easily hit it to the back of the court, where it is difficult to return.
EXAMPLES: Peach, Daisy
SPEED
If you want to get to the ball fast, these are the guys to choose. They're not particularly strong, but they can move around the court with ease.
EXAMPLES: Yoshi, Diddy Kong
TRICKY
Skilled players can make good use of these characters. Their ability to hit wild curve shots can confuse unprepared opponents.
EXAMPLES: Boo, Bowser Jr.
POWER
These are the "big guys," and as you might imagine, they're plenty strong. They'll send the ball flying back to your opponent.
EXAMPLES: Donkey Kong, Wario, Bowser
DEFENSE
As a defensive player, Waluigi can reach balls that would be out of range for other characters. It's tough to sneak a shot past his lanky limbs.
EXAMPLES: Waluigi
In addition to the many Mario-universe characters, you can choose to play as your Mii. This personalized character doesn't have any predefined skills, so it's up to your natural abilities to win the cup.
From the MarioWiki:
Playable Characters:
Mario
Luigi
Peach
Bowser
Daisy
Donkey Kong
Diddy Kong
Yoshi
Wario
Waluigi
Bowser Jr.
Boo
Mii
Non-playable characters:
Lakitu
Toads
Piantas
Nokis
Goombas
Mecha-Koopas
Penguins
Shy Guys
Koopas
Courts
Mario Stadium
Peach's Palace
Bowser's Castle
DK Jungle
Mushroom Valley
Penguin Iceberg
Wario Dunes
Source: http://www.nintendolife.com/forums/3ds/mario_tennis_discussion?start=60
"To go along with the new touch-screen controls is a gameplay enhancement that takes advantage of the N3DS system's gyro sensor. Holding the system flat forces the camera into a mostly overhead view of the court - typical for tennis games. If you put the N3DS in a vertical position, though, the camera shifts behind your character. From this point of view, you aim your shots by simply moving the system left and right. While playing in this Dynamic View mode, your character will automatically run to where the ball is approaching, leaving you free to choose your shot and aim it properly. Not having to worry about reaching the ball means casual players will especially benefit from this mode. It's also worth mentioning that the N3DS automatically turns off its 3D capabilities while in Dynamic View, as the frequent movement of the system would disrupt the stereoscopic effect."
There are 13 characters available at the start of Mario Tennis Open. Each one has a special attribute that will affect how you play as him or her. The information here will help you pick the character that's best for you.
ALL-AROUND
Beginners will want to start with these characters. They have no particular strengths or weaknesses, but they're well-balanced and easy to control.
EXAMPLES: Mario, Luigi
TECHNIQUE
These characters have great control over the ball, allowing them to easily hit it to the back of the court, where it is difficult to return.
EXAMPLES: Peach, Daisy
SPEED
If you want to get to the ball fast, these are the guys to choose. They're not particularly strong, but they can move around the court with ease.
EXAMPLES: Yoshi, Diddy Kong
TRICKY
Skilled players can make good use of these characters. Their ability to hit wild curve shots can confuse unprepared opponents.
EXAMPLES: Boo, Bowser Jr.
POWER
These are the "big guys," and as you might imagine, they're plenty strong. They'll send the ball flying back to your opponent.
EXAMPLES: Donkey Kong, Wario, Bowser
DEFENSE
As a defensive player, Waluigi can reach balls that would be out of range for other characters. It's tough to sneak a shot past his lanky limbs.
EXAMPLES: Waluigi
In addition to the many Mario-universe characters, you can choose to play as your Mii. This personalized character doesn't have any predefined skills, so it's up to your natural abilities to win the cup.
From the MarioWiki:
Playable Characters:
Mario
Luigi
Peach
Bowser
Daisy
Donkey Kong
Diddy Kong
Yoshi
Wario
Waluigi
Bowser Jr.
Boo
Mii
Non-playable characters:
Lakitu
Toads
Piantas
Nokis
Goombas
Mecha-Koopas
Penguins
Shy Guys
Koopas
Courts
Mario Stadium
Peach's Palace
Bowser's Castle
DK Jungle
Mushroom Valley
Penguin Iceberg
Wario Dunes
Source: http://www.nintendolife.com/forums/3ds/mario_tennis_discussion?start=60