We also had numerous occasions where the game didn't recognise a swing at all, despite our action changing very little from one shot to another. Once in a blue moon is fine, but this happened too often to be ignored. Drop and lob shots also break the illusion somewhat as they can only be triggered while holding A or B, rather than simply making the real-life motion. It's far from game breaking, and works fine, but it's a shame a button press is required given how well the other controls work most of the time.
As in all modern sports games, the career mode is the real meat of the package, giving you the chance to take a custom character through the elite tennis ranks as you attempt to win the four grand slams. While the four majors are present and correct, that's it. You take part in practice matches and challenges before each big tournament kicks off, but these all take place at the same major venues. There are no small-time tournaments to take part in at all. The way you win character upgrades through beating pros, and stars by generally playing well, is a nice touch, but the career mode definitely feels slight.
Outside of that there's the expected multiplayer options, including online play, a fitness mode that tracks how many calories you've burnt with your Grand Slam Tennis sessions, numerous mini-games (although these are of a rather serious nature and don't feature the kind of mayhem seen in SEGA's VT series) and a practice mode. There's certainly enough here you keep you playing for some time, but the big draw is multiplayer and not the career mode. Incidentally, the game works without Wii MotionPlus, but it's not nearly as much fun - if you want the full experience you'll need Nintendo's new accessory.
A final note: Grand Slam Tennis is tiring. It might be an obvious thing to say, but don't expect to be playing this for hours on end. While there's no need to run around the living room, the constant need to swing your arm will cause a few aches and pains. While you can get away with couch play when messing about with Wii Sports Tennis, sit down during Grand Slam and it's just not the same.
If you're after the most realistic feeling tennis game on the market, Grand Slam Tennis for Wii is it, when it works. MotionPlus-enabled shots can be performed by feel alone (as long as you're not lobbing or performing drop shots) and this will be enough for a lot of gamers – just be prepared for a fair few annoying moments. If you're after an in-depth single-player experience you might be disappointed though, as what's on offer here is geared around playing with friends.