Enthralling ball-juggling puzzle solving.
Don't let the aesthetic fool you. Underneath World of Goo's facetious simplicity lies a game that's challenging to master. The aim is to herd a preset number of goo balls from point A to point B, the latter being a giant tube sucking in whatever goo balls come near it. To actually reach that exit, you'll need to drag and drop those slimy rascals to build a path - be it a tower, bridge, rope or platform - for the other goo balls to travel across. This is easier said than done since each new structural goo ball you add, taunts the laws of gravity just a bit more.
You'll quickly discover that reinforcement becomes a key factor: towers need a wide foundation for you to stack on like a house of cards, while bridges need plenty of underlying supports to keep them from collapsing. As long as you have enough goo balls left to meet the level requirement, you can make your constructions as sturdy as you want. Or, at least as sturdy as jiggling slime tethers would allow.
Throughout the course of the game different types of goo balls are introduced; they can stick to any surface, or they can be torn out of a construction and reapplied elsewhere, or they are like a balloon and can lift small goo clusters into the air effortlessly. But with new toys come new hazards: spiked walls, open flame or hurricane winds make you think twice about how to approach each scenario, since the death of even one structural goo ball can bring your entire construction down.
The puzzles themselves are pretty straightforward. You never have to wonder about how to get to the exit, but knowing where your fortifications need to be planted could take a few retries, especially once the game makes you build on water or inside a constantly rotating drum. Even if you feel like you've had your belly full of a specific puzzle, there are two scenarios available to you at any time so that you're never stuck in a part you enjoy less.
The puzzles also tie into a neat meta-game: every goo ball you extract is sent to the Tower of Goo where you are allowed to build a tower as high as you can, with the height of other players' towers appearing as floating texts around yours. This creates a competitive edge: it's one thing to finish a level by meeting the goo requirement, but if you finish it with spending as little goo balls as possible on the path, you can extract more goo balls to use in your architectural wonder.
The 50-ish levels should keep you occupied for about 10 hours but if you truly want to call yourself a goo-ru (you were fairly warned) you can try your hand at one of the level-specific OCD challenges. These require you to finish a level within a set time, use a limited amount of moves, or extract as big a number of goo balls as possible. They often require you to approach the gameplay in ways not found in the actual game, making them very hard but very rewarding to complete.
One of the game's most inviting features is that it only uses a single button. Building is a matter of dragging and dropping goo balls, you can undo a small amount of your actions by clicking the fireflies buzzing around the screen's edges and once you unlock the whistle, you can lure the goo balls to a certain position. However, this single-button-service also has a downside: it can be stupidly difficult to try and select a specific goo ball when they're packed together.
This simplicity unfortunately also carries over to the visual design: it looks like an indie game and I don't mean that as a compliment. The colours are a little too muted, the shapes are elementary and the small amount of people that is shown in the game consists of crudely drawn cut-outs who simply don't fit in with the rest of the picture. That said, the level select screens are really impressive and the game does some unexpected and creative things with its aesthetic later on.
Whatever the visuals may lack is made up for by the music, with what I consider one of the best soundtracks I have ever heard in games. Sure, the loops are obvious and not very long but they are surprisingly diverse and work harmoniously with the theme of each puzzle, layering a playful sense of discovery over green-hilled gardens, or haunting guitar wails over a storming sky.
World of Goo is one of those games that helped put indie development on the map, and with good reason. It's fun, charming, challenging, and a whole bunch of other superlatives wrapped up in one cheap package that's well worth the price of admission.