Blades are one of the hazards found in World of Goo. They can destroy structures and kill Goos with ease. Usually these are best to be avoided. They can, however, be used to make a small structure which can be used with Balloon Goo to float and reach some locations.
Unlike gears, which often act as a help to goos, blades are always dangerous. If part of a goo structure is destroyed, not only will those goo be lost, but Goos on the legs of the shattered Goos will also fall. Blades pose a large threat to players trying to achieve OCD, as once a goo is destroyed by a blade, unless using a time bug, there is no bringing it back.
Blades are found in several levels, though most often in levels with airflow or warped gravity. As in Graphic Processing Unit, Bulletin Board System, and Blustery Day, the blades are placed in the level as a nuisance the player must overcome.
Differences from gears
Blades are similar to gears in the aspect that they both destroy Goo structures. However, blades can additionally kill Goo Balls themselves. Goo structures can lean very close to a blade without being hurt, similar to Goos fitting in between spikes, but they will be unable to touch the wall the blade is on.