The complete post production of the movie - including the creation of the CG scenery in the first part of the movie and the frame-by-frame drawing of all the faces of the mobile phones in the second part - was completed in only three weeks.
The movie was shot using a motion control rig. A week before principal shooting however, the software failed and the rig could not be properly re-calibrated.
Due to that fact all tracking shots except for one big establishing shot were deleted from the script and transformed into steady shots.
Even the one remaining tracking shot didn't make it into the final movie. 3D tracking could not be done properly because of the very short post production time. That's why the film starts with a wide shot without any camera movement.