Each chapter is relentless in its wit and imagination, with each addition explained to you by the funny, oblique tips left on each level by the helpful, unseen Sign Painter. The new goos that get introduced are mixed to create levels of ever greater complexity. For example: using balloon goos to raise a powerline of black goos higher at one end, creating a slope and causing a giant beauty goo – that’s a goo with a make-up-laden face – to roll forward and be broken apart into smaller beauty goos that can then be sucked through the pipe. Those themed levels we mentioned earlier, like the beauty pageant? Often realised in very silly ways.

While we desperately want to tell you about how awesome this level is or how great that goo is, we can’t. You’d hate us for it when you played the game and missed out on the joy of discovering them yourself. Most puzzle games have nothing to spoil but the solution, but World of Goo has a rambling, hodgepodge narrative full of delightful moments. As we played, people gathered around our desk to watch. Multiple people have told us they applauded during the occasional cutscenes that play upon finding a solution to certain levels.

Those solutions are never immediately obvious. The majority of levels, even early on, will give you pause. “How the hell do I do this? It’s impossible.” Then you start to build, working out the solution as you go. The levels grow in complexity as the game advances and are always challenging, but they never outstrip your ability to finish them. They never require luck and they never exasperate. The result: you’re constantly made to feel like some sort of mad architectural genius. A mad architectural genius who’s really good at World of Goo.

Take, for example, an early level where you begin on a platform below an outcropping of rock and cogs, blocking your path to the pipe. You have to build left, stretching out over some water, then up past the rock and then back to the right toward the pipe. If you get too close to the rock face, spinning cogs will break apart your structure, causing goos to fall to their mucky demise. At first glance it seems that there’s no way to do it, but somehow it proves simple, the goos always hanging together just a little bit more than you expect them to.

You feel a constant sense that you can do better. In our original preview, we identified the perfect cultural analogy to World of Goo in the movie Schindler’s List. Goos that are used to make part of a structure can’t travel to the exit, thus can’t be saved, thus are left behind forever. There’s always the feeling that by doing things differently you could have saved so many more. The OCD achievements play on that: Obsessive Completion Distinctions are gained for finishing a level while meeting some more stringent criteria. For example, reaching the exit in under nine seconds, or doing it in only 17 moves, or saving 61 goos when only 20 are normally required.