You are part of a simulation and your objective is to use a Spaceship to destroy Beacons that power a large inter-dimensional Portal, before it is opened and a powerful creature only known as "The Destroyer of Worlds" is brought to destroy our universe.
Aperture Science could be described as a heaven for all the brightest minds and their remarkable yet crazy experiments. Ever since has Cave Johnson shown interest in exploring the Multiverse, Aperture scientists were hard at work to create their own.