Propulsion Gel

Propulsion Gel is a substance created by Aperture Science, used in the Aperture Science Enrichment Center, and slated to appear in Portal 2. It is first created in 1998 by Aperture Science as a diet aid, made out of liquefied, non-toxic fiberglass insulation. Marketed under the name "Propulsion Pudding", the gel increases the velocity of food that follows it through the digestive tract, leaving the body no time to absorb calories. It is pulled from shelves however, when it is discovered that digestion plays several vital parts in the eating process, such as breaking food into manageable sizes before violently expelling it from the human body; the gel does not allow the former.

Overview
The Propulsion Gel, orange in color, is slated to appear in Portal 2. It is to accelerate the velocity of any object it touches, giving them largely increased speed capabilities and allowing them to vault over pits or reach the far end of a long expanse quickly enough to best a ticking clock. Propulsion Gel is to be spilled through a vent, be dynamic, and play quite well with portals. Placing one portal under a vent and another in another area of the Test Chamber allows using the paint far from the vent, allowing to progress past a given obstacle.

Behind the scenes

 * The expanded gameplay produced by Repulsion Gel and Propulsion Gel alone appears to be extremely satisfying, and Valve indicated a willingness to include more if it sees fit.


 * This feature directly reuses the paint feature seen in the student video game Tag: The Power of Paint, as the whole team has been hired by Valve to develop it for Portal 2. The Propulsion Gel to be seen in Portal 2 mirrors directly Tag’s red paint, while the Repulsion Gel mirrors the green paint. It is however unknown if Tag’s blue paint, a sticky paint allowing to walk on any surface, horizontal or vertical, will be reused for Portal 2. It is also unknown if a paint gun counterpart will be present.

List of appearances

 * Portal 2