After months of reading praise for World of Goo, I finally decided to try it out a few weeks ago. I downloaded the demo, installed it, fired it up... and came away largely impressed. So, I picked up the game on Steam and spent the last week playing – and beating – it. World of Goo is a genuinely fun game that's easy to pick up and challenging just to the right degree. My caveats with it are small and few, especially in light of the fact that it is such an entertaining and unique game.

At its core, World of Goo is a simple physics simulation with a little bit of Lemmings thrown in. Blobs of goo roam around the level, and can be picked up and placed within a certain proximity of other blobs to form connections. Using multiple blobs of goo, you can build towers, bridges, ropes, etc. all in an effort to get the remaining goo (which will climb around your structure as you build it) from one end of the level to the other. The level is complete when a pre-set number of globs have reached safety in this manner.

As you would expect, different types of goo are encountered as you make your way through the game's five worlds. The generic gray goo attached to other goo once and cannot be moved, green goo can be attached and detached at your whim, clear goo can only attach to one piece of the structure at a time (good for ropes), and so on.

There are multiple levels of challenge in World of Goo. For example, in one level you are tasked with constructing a bridge across a pit of spikes. The spikes will destroy any goo that touches it, even if they are part of a structure, so when you build a bridge to cross the gap, care must be taken to avoid having any part of the structure being pulled down into them. One part of the goo-bridge being popped by the spikes can throw off the balance of the entire creation, resulting in a structural failure of catastrophic proportions and (usually) all of your goo falling into the pit. Balloons have been provided however, so your bridge won't collapse after extending too far if they are use correctly.

Even this simple scenario presents many challenges for thought and design. Should the bridge be built at an upward angle to further combat gravity? How many pieces of goo should be used to make the bridge stable? At which points should the balloons be placed to ensure the most stable bridge? These are common dilemmas one faces when traversing the levels in World of Goo.

Fortunately, levels in the game are usually fairly straightforward, so in the circumstance that you need to restart a level, there's usually not too much you'll need to do to get back to where you were when you failed before. The physics in the game are very consistent, so you rarely feel that you are leaving the fate of your goo to luck, and you're also given a handful of chances to undo previous moves.

World of Goo's graphics are both a thrill and a disappointment at the same time. The visuals are bright, colorful, and well animated, and even though the style of graphics make them look almost as if they were thrown together rather quickly, there is a polish in the details that even blockbuster games with million dollar budgets have a hard time achieving. Everything in the game that the player can interact with gives great feedback as the mouse bounces around the screen. Color is used liberally and wonderfully. Physics objects are easy to pick out against the terrain, and animations are smooth and fun. The whole game has a very Worms-like quality to it, if you get what I mean.

The only shortfall in the graphics for Goo is that the game runs at 800 x 600, and that's all the graphics were made for. Sure, the game even expands to look fine on my widescreen monitor, but it is slightly disappointing to me that the artwork couldn't have been rendered at a slightly higher resolution, if only for the PC version. I actually wish the entire game could have been rendered as textured vector graphics, since the underlying physics engine probably uses polygons to define all the shapes anyway, but alas, it is what it is - a beautiful, if slightly pixelly, World of Goo.

The audio end of World of Goo is equally as brilliant as the visuals. The music included in the game is very well done, and suits each level's experience well, and the sound effects are spot-on. You'll grow to love all the little squeals and squelches of the goo globs as you form them into structures and progress through the game. The soundtrack for the game can be downloaded for free at Kyle Gabler's blog.

Overall, I had a lot of fun with World of Goo. The level progression is linear, but there are a few points where you can choose to do one level over another, so if one is initially a bit too challenging, you can come back later. And if you get completely stuck (or just bored) you can always go to the World of Goo Corporation to play around with the extra balls of goo you've saved, to try to build a tower. In this mode, you can see other players' tower heights (represented by clouds) as you get farther and farther into the sky. This is a neat little feature that really just adds to the fun, and challenge, of building a huge tower. And it's little things like this that really push World of Goo beyond the realm of your standard casual game.

Sure, the whole concept of World of Goo sounds a bit strange. It certainly looks a bit strange, I'll give you that. But try out the demo anyway, and if you like it, buy the game (don't contribute to the horrible Goo piracy). The two-man team of 2D Boy has put together a wonderful experience with World of Goo, and their achievement is our opportunity for some fun!