The Portal concept is officially complete. From the energy ball to transferring the Weighted Companion Cube. I would suggest anybody to download it here first, especially that there is a radio tune of "Still Alive" in this map. Like the actual Portal Game, you can't cast portals on black metal terrain or on non-walkable terrain. You can't stack both portals at the same spot, so don't bother. There are Missile Traps that 'reset' the Portal Gun as if you are walking through the energetic field in Portal.

The basic controls are:
W - Cast Portal
U - Switch Portals