I own this game on the PC through Steam but I've put this review in the Nintendo forum because I first played the game on the Wii - and the Nintendo forum needs some love anyway!

Game name: World of Goo
Players: 1-2 (apparently the WiiWare version includes 2 player co-op)

Review:

World of Goo is a well executed puzzle game. It's a remarkably simple concept but one that provides hours of entertainment. The basic premise of the game is that you have to help the goo balls get to the pipe at the end of the level. This is usually done by picking up your goo balls and using them to construct bridges or towers to link to the pipe so that any remaining goo balls can safely travel to the pipe and be sucked away to fulfil their life's purpose. For the first few levels it really is that easy, simply build a bridge or tower and you complete the level. As you progress, however, you'll find that the answer isn't always so simple. There are a number of hazards including pitfalls, wind turbines (whose blade will happily chop your goo balls into very tiny pieces) and even fire and explosives. To combat these new threats you are provided with different species of goo balls, some of which can be connected to your 'tower of goo' and then re-connected, some which are flammable and can be used to chain together a fuse for an explosive, others can float and can be used to keep a long bridge from collapsing or, occasionally, to float away with some goo balls attached. Each level also comes with signs left by the enigmatic 'sign painter' many of which contain entertaining quotes and often give you clues on how to proceed with the level.

There are 4 stages with a good number of levels which get increasingly difficult as you progress and, for those perfectionists out there, there is an 'OCD' goal for every level. Sometimes this is to save every goo ball and other times to complete the level in a certain time or number of moves. Most of them are very difficult to achieve without a lot of patience and clicks of the retry button.

The game's cartoony 2D graphics work very well and give the game a very approachable feel to it. The background music is perfectly suited to the game and the sounds the goo balls make can be quite amusing at times.

All in all it's a very well constructed puzzle game which can take up more than a few hours of your life. Some of the levels are very difficult to work out at first and I'll admit to having spent a few minutes just looking around some of the levels to figure out which way to send my goo balls. The developer, 2D Boy, is a 3 man team who has managed to create a title which I personally believe is better than most retail games on the Wii at this moment in time. I'll look forward to any content from them in the future.

Ratings
Graphics: B
Sounds: A
Gameplay: A
Replayability: B-C (depending on if you're tenacious enough to go after the OCD awards)

Overall score: A

Now I just need to make space on the Wii for it...