Speed Gel (Mechanic)

Speed Gel, known in later version of the game as "Propulsion Gel" it's a gel that lets you quickly accelerate when moving over surfaces covered in it. Objects coated in it would slide quickly across all surfaces. The Gel Originated from Tag: The Power of Paint and was ported to Paint (Project) which then was merged with Portal 2 in late 2009.

Origin
Speed Gel originates from Tag: The Power of Paint, where it was orange. It would let you speed up.