On a purely personal note, I'm a bit annoyed at Mario Power Tennis' version of Shy Guy. He was my main man in Mario Tennis 64. My lefty Shy Guy was simply unstoppable. Although this iteration of Shy Guy has a nice defensive power shot, I absolutely can't stand his stupid electrified lob -- a pitiful excuse for an offensive power shot. Sure it comes in handy during doubles matches, but it's not very good in a singles match. I was so put off by Shy Guy's offensive power shot that I had to find a new character and was dismayed when I discovered that Daisy is the character best suited to my playing style. Oy.
It's hammer time with Mario.
The only quibbles I had with the game's single-player offerings were in regards to doubles partner AI and the mini-games. Your computer-controlled partner in doubles matches hogs the ball at net way too much, often getting in bad positions and places a doubles player should not go. It's unusual because the opponent AI in singles is pretty good, particularly at the higher difficulty levels. I wasn't too big on the mini-games, but I can see the appeal; though they didn't work for me, I acknowledge the variety they add to the game.
Multiplayer is where the game really shines. Playing with one to three of your friends is an absolute blast. Mixing and matching the different players, courts, and mini-games gives you and your pals an almost limitless permutation of tennis fun. The game is very good on its own, but it excels when you bring friends into the mix.
Though Mario Power Tennis is quite different from the previous version, it's a superior product in almost every way. It's based on excellent gameplay mechanics that are taken in really interesting directions through gimmick courts. Mastering each player will take dozens and dozens of hours. Multiplayer games are a total riot. Though it doesn't look or sound as good as other games on the market, there's no denying the sheer amount of fun this game offers even if Camelot ruined Shy Guy for me.