You get this when you complete the last mini-part of the game after the laboratory level. This is mostly one long (very impressive) cut-scene, although on two occasions you will have to interact with the panel in front of you (just put your hand into it when it opens up and shows you a hand) and toward the end (after the long speech from the person you meet here is done) you have to point your hand to the stuff above you and pull the trigger for a few moments. The cut-scene will continue into the closing credits and the achievement for completing the first episode will unlock.