In this week’s informational video, Aperture Science founder Cave Johnson explains why robots’ll get you the biggest bang for your testing dollar.

Cave Johnson shows off more Portal 2 Co-op Gameplay in this new trailer, but without actually showing any real gameplay.  This is the second video in the ‘Aperture Science Invest Opportunity,’ a new documentary video series Valve plans on releasing every week up until Portal 2′s Release.

Portal 2 releases April 19th for Xbox 360