World of Goo operates in the same moral space as the Psygnosis classic, Lemmings: You sacrifice the many for the benefit of the few. Contrary to what I depict in the comic, the Gooballs actually lose their adorable eyes and cheery individuality as you put them to use. You are, in effect, murdering them as you lash them together to build your scaffolding to salvation.
Imagine you and nine other people are stuck in a hole. Someone then comes up with a plan: Let's kill seven of us, and use their bones to build a ladder for the other three! This is World of Goo.
Sorry to get all morbid on you. The game isn't nearly as dark as I make it sound. It's fun and cheerful and the Gooballs will actually delight in your Stalinesque rule over them.
Shamus Young is a programmer and writer by trade, videogame nitpicker by inclination. If you have the patience for more of his ramblings, they can be found at ShamusYoung.com.