portal 2 co-op mass and velocity 5 Published 13 years ago • 8K plays • Length 8:09 Download video MP4 Download video MP3 Similar videos 17:25 playing portal 1 and 2 with one set of portals 8:48 portal 2 wheatley's betrayal 4k 18:44 portal 2 - chapter 6: the fall - full walkthrough 2:47:34 portal 2 - full game walkthrough 3:42:52 portal 2 full gameplay (all chapters) 1:57 portal 2 - full co-op trailer