Haha this was simply brilliant in execution, this was clever in that I enjoyed it more thanks to your voice overs adding so much value. I was shocked and impressed you included the use of voice over audio at first and then lost it when they were like 'has anyone seen david'... I grinned like a big kid. Bravo! ~ it truly is the simple things that when executed in a suprising way, drive a great experience :D
One thing to touch on would be that the feedback for the elevator was misleading and I found myself with the bag at the elevator heading away as I was unaware i had to WAIT for the elevator, I thought I had forgot something.
Might be a silly 'hand holding' thing I like to see in games these days but I figure it out eventually.
Great Job and for 12 hours... not too bad at all! :)