You can play friends or strangers over Nintendo's network, or play friends locally via Streetpass. Local pals won't even need a copy of the game. One cartridge between two 3DS systems allows you to play against each other, though with limited arena choices. You can also play on your own against tough computer opponents.
After playing a handful of strangers online, I realized that the in-game tutorial and paper control guide were lacking. Folks had figured out how to spike and spin balls in ways not touched upon in the single-player gameplay. After eight hours sunk into the game, I am still not clear how to put spin on a ball or how to charge a serve correctly.
As you play, you'll unlock items like outfits and new rackets in the store. To get any new item is a two-step process: unlock it by playing in a tournament, then purchase it with money earned from playing a series of so-so minigames. But once you purchase a new racket with improved power shots and shoes to speed you down the court, don't expect to apply the new duds to any Mario universe characters. The accessories are designed for your Mii avatar character, a bummer if you enjoy playing as Diddy Kong or Peach. I understand it would be hard for a shirt and shorts to fit on, say, Boo the ghost, but the Nintendo team could have had fun and been a little creative when skinning the franchise characters.
At times volleying can be as fun as an intense game. Other times I found myself bored, waiting for a power up to just end the match.
Pausing is extremely hard to do, but this is inherent in the sport. So be warned, once you start up a Mario Tennis volley, don't plan to put it down or talk to anyone for an undetermined period of time. Apologies to my wife in advance.
The game's 3D is serviceable. Nintendo's team knows how to design and execute 3D space best, though Mario Tennis Open is focused on making the court a shadow box of depth rather than sending objects flying at the screen. There is no "first person" mode.
Suggested retail price is $39.99, a fee worth paying if you are itching to face off with friends. This is the game's biggest strength. Otherwise, if your friends aren't carrying 3DS portables with them, you're gonna have a bad time. For the same money, a game of this caliber would likely cost $4.99-$9.99 on say, an iPad. We wouldn't go as far as to say Mario Tennis Open is a 99- cent minigame, but the limited possibilities of tennis gameplay should probably never call for a price over $20.