It's good, but it's not right!!!
The problem with it is that there's not much variation to the tournaments. Its a great game to pick up and play for a short time, to get a quick fix of it. But when you try and play it for a longer period of time it starts to get a bit tedious.
Don't get me wrong, for a game that you would have assumed would be rubbish from the start, Table Tennis has done a fantastic job on making an unknown sport accessible to everyone.
It's one of those games that everyone who has a 360 owns (like Perfect Dark Zero) and you can get it pretty cheap, used from ebay (£5/$10). It may not blow your mind, but it's definitely worth having for the occasional play.